2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing • 2003 Ford Crown Victoria • MotoLogic ... Suspension 2003 Crown Victoria/Grand Marquis/Marauder Workshop Manual: DIAGNOSIS AND TESTING Procedure revision date: 12/06/2006 Vehicle Dynamic Suspension
2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Vehicle Dynamic Suspension - Diagnosis and Testing Subarticles Principles of Operation Inspection and Verification Rear Air Suspension Control Module Diagnostic Trouble Code (DTC) Index Symptom Chart Pinpoint Tests SECTION 204-05: Vehicle Dynamic Suspension 2003 Crown Victoria/Grand Marquis/Marauder Workshop Manual DIAGNOSIS AND TESTING Procedure revision date: 12/06/2006 Vehicle Dynamic Suspension Refer to Wiring Diagrams Cell 41, Rear Air Suspension for schematic and connector information. Special Tool(s) Worldwide Diagnostic System (WDS) 418-F224 New Generation STAR (NGS) Tester 418-F205 or equivalent scan tool Vacuum Tester or equivalent 014-R1054 73 Digital Multimeter or equivalent 105-R0051 Principles of Operation https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 1/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic WARNING: Before repairing or installing any air suspension component(s), turn off the air suspension switch or disconnect the battery ground cable to prevent vehicle damage or personal injury. WARNING: Do not attempt to install or inflate any air spring that has become unfolded to prevent vehicle damage or personal injury. WARNING: Failure to observe the following procedures can result in a sudden failure of the suspension system. WARNING: Any air spring which is unfolded must be refolded prior to being installed in a vehicle. WARNING: The air spring refolding procedure should not be used for an air spring which has never supported the vehicle's weight while in the correctly folded position. WARNING: Vehicles with an incorrectly folded air spring(s) found after the vehicle has been driven, must have a new air spring installed. WARNING: Do not attempt to inflate any air spring which has collapsed while deflated from the rebound hanging position to the jounce stop. WARNING: When installing a new air spring, care must be taken to not apply a load to the suspension until the air springs have been inflated using the air spring fill procedure. WARNING: After inflating an air spring in the hanging position, it must be inspected for correct shape. The air suspension system is designed to improve ride handling and general vehicle driving performance. Rear Air Suspension Control Module CAUTION: Before diagnosing the rear air suspension system, carry out the RAS module self-test. If a DTC is present, follow the diagnosis and testing procedures. If no DTC is present, check the vehicle ride height by following the ride height adjustment procedure in this section. If the system cannot reach the correct ride height, check all of the air supply lines and connections for leaks/blockage/or damage, height sensor integrity, and/or compressor relay operation before installing a new air compressor. A microprocessor controls the air suspension system. The microprocessor and its supporting hardware are contained in the rear air suspension control module. The rear air suspension control module responds to signals from various sensors in the vehicle to maintain the programmed ride height while the vehicle is either moving or stopped. The rear air suspension control module accomplishes this by opening and closing solenoid valves to control the amount of air in the air spring(s). The rear air suspension control module turns on the compressor by applying voltage through the compressor relay to inflate the air spring(s) and raise the vehicle. The rear air suspension control module opens the vent solenoid to lower the vehicle by releasing air from the air spring(s) in response to signal inputs from the air suspension height sensor. The air suspension module has a preprogrammed trim height. Whenever a door is opened, the air suspension will compensate in order to bring the vehicle back to the preprogrammed trim height. Air Suspension Switch https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 2/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic CAUTION: The air suspension switch must be turned to the OFF position when the vehicle is hoisted, jacked, towed, jump started, or raised off the ground, to avoid unnecessary operation of the system and possible damage to the air suspension system components. The air suspension switch provides a signal to the rear air suspension control module in the ON position to activate the system to maintain the programmed vehicle height. Air Compressor NOTE: The compressor contains a thermal overload circuit breaker. The circuit breaker automatically resets after a cooldown period and after being tripped by excessive compressor motor heat. The air compressor assembly consists of the compressor pump, electric motor and vent solenoid (must be installed as an assembly). Air Suspension Rotary Height Sensor One air suspension height sensor is mounted on the vehicle. The air suspension height sensor sends a voltage signal to the air suspension control module. The output ranges from approximately 4.75 volts at minimum height (when the vehicle is low or in full jounce) to 0.25 volts at maximum height (when the vehicle is high or in full rebound). Install a new air suspension height sensor as a unit. When the air suspension height sensor indicates that the rear of the vehicle is lower than trim height under normal driving conditions, the air compressor will turn on and pump compressed air into the air springs. When the sensor indicates that the rear of the vehicle is raised above trim under normal driving conditions, this will cause the air to be vented from the air springs to lower the vehicle back to its trim height level. Solenoid Valve, Air Spring WARNING: Never rotate an air spring solenoid valve to the release slot in the air spring end cap fitting until all pressurized air has escaped from the air spring. The air spring solenoid valve allows air to enter and exit the rear air springs during height adjustment operations. The air spring solenoid valve is electrically operated and controlled by the air suspension control module. Inspection and Verification CAUTION: Before diagnosing the rear air suspension system, carry out the RAS module self-test. If a DTC is present, follow the diagnosis and testing procedures. If no DTC is present, check the vehicle ride height by following the ride height adjustment procedure in this section. If the system cannot reach the correct ride height, check all of the air supply lines and connections for leaks/blockage/or damage, height sensor integrity, and/or compressor relay operation before installing a new air compressor. 1. Verify the customer concern. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 3/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic 2. NOTE: If the door ajar indicator is illuminated, repair the door ajar indicator. For additional information, refer to Section 413-09. Visually inspect for obvious signs of mechanical and electrical damage. Visual Inspection Chart Mechanical Restricted suspension movement Excessive vehicle load Cut, severed or crimped air line(s) Incorrectly mounted, damaged or disconnected height sensor Damaged air spring(s) Electrical Central junction box (CJB) mini fuse: 16 (15A) Battery junction box (BJB) mini fuse: 114 (30A) 115 (50A) Loose or corroded connectors Air suspension switch Damaged air spring solenoid(s) 3. If the concern remains after the inspection, connect the scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle: check that the program card is correctly installed. check the connections to the vehicle. check the ignition switch position. 4. If the scan tool still does not communicate with the vehicle, refer to the scan tool manual. 5. Carry out the DATA LINK DIAGNOSTIC TEST. If the scan tool responds with: CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Section 418-00. NO RESP/NOT EQUIP for rear air suspension control module, Go To Pinpoint Test A. SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out self-test diagnostics for the rear air suspension control module and system pneumatic test. 6. If the DTCs retrieved are related to the concern, go to Rear Air Suspension Control Module Diagnostic Trouble Code (DTC) Index to continue diagnostics. 7. If no DTCs related to the concern are retrieved, GO to Symptom Chart to continue diagnostics. Rear Air Suspension Control Module Diagnostic Trouble Code (DTC) Index NOTE: If the air suspension control module C2131b is disconnected before the air suspension control module C2131a, DTCs C1830, C1770, C1790 and C1795 will be retrieved and must be cleared before an accurate list of continuous DTCs can be retrieved. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 4/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Rear Air Suspension (RAS) Control Module Diagnostic Trouble Code (DTC) Index DTC Description B1317 Battery Voltage High Source RAS Module Go To Pinpoint Test C. Action B1318 Battery Voltage Low RAS Go To Pinpoint Test C. Module B1342 ECU is Defective RAS Module INSTALL a new rear air suspension control module. REFER to Air Suspension Module in this section. TEST the system for normal operation. B1566 Door Ajar Circuit Short to Ground RAS Module Go To Pinpoint Test D. B2477 Module Configuration Failure RAS REFER to Section 418-01. Module C1445 Vehicle Speed Signal Circuit Failure Anti-Lock Brake System (ABS) Module Section 206-09. C1724 Air Suspension Height Sensor Power Circuit Failure Rear Air Go To Pinpoint Test E. Suspension Control Module C1726 Air Suspension Rear Pneumatic Failure RAS Go To Pinpoint Test F. Module C1760 Air Suspension Rear Height Sensor High Signal Circuit Failure RAS Go To Pinpoint Test G. Module C1770 Air Suspension Vent Solenoid Output Circuit Failure RAS Control Module Go To Pinpoint Test H. C1790 Air Suspension LR Air Spring Solenoid Output Circuit Failure RAS Go To Pinpoint Test I. Module C1795 Air Suspension RR Air Spring Solenoid Output Circuit Failure RAS Module Go To Pinpoint Test I. C1830 Air Suspension Compressor Relay Circuit Failure RAS Go To Pinpoint Test J. Module C1840 Air Suspension Disable Switch Circuit Failure RAS Go To Pinpoint Test K. Module https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 5/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic C1897 Steering VAPS Circuit Loop Failure RAS REFER to Section 211-00. Module C1964 Air Suspension Air Compressor Request Exceeded Maximum Timing RAS Module DTC code C1964 indicates that the air compressor has overheated and is unable to enter the self-test. Allow the air compressor to cool down for approximately five minutes. CLEAR the DTC. REPEAT the self-test. U1026 SCP Invalid or Missing Data for Engine RPM PCM CARRY OUT the PCM Self-Test. Symptom Chart Symptom Chart Condition NOTE: Be sure that air suspension disable switch is in the ON position before determining that a fault condition is present. No communication with the rear air suspension module Possible Sources CJB Fuse 16 (15A). BJB Fuse 114 (30A). Circuitry. Data link connector (DLC). Rear air suspension control module. Unable to enter self-test Rear air suspension control module. Did not detect open and close door signals Circuitry. Door ajar switch. Lighting control module (LCM). Rear air suspension control module. Action Go To Pinpoint Test A. Go To Pinpoint Test B. Go To Pinpoint Test D. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 6/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Scan tool indicates self-test failure when attempting to run self-test Air suspension switch Circuitry Go To Pinpoint Test K. The compressor is inoperative Circuitry. Air compressor relay. Air compressor. Go To Pinpoint Test L. The air compressor continuously cycles with the ignition switch in the OFF position and no DTC is set Circuitry. Air compressor relay. Air suspension control module. Go To Pinpoint Test M. Air suspension system works with air suspension switch in the OFF position Air suspension switch. INSTALL a new air suspension switch. TEST the system for normal operation. Uneven vehicle height Pneumatic fault. Air suspension height sensor. Air spring solenoid. Air compressor. Air spring. Air suspension control module. REPAIR as necessary. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 7/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Incorrect vehicle trim height Incorrect ride height adjustment. Incorrect height sensor calibration. Incorrect air suspension module calibration. SET the ride height. REFER to Ride Height Adjustments in this section. Rear suspension component damage. INSPECT and REPAIR the rear suspension components as necessary. REFER to Section 204-02. Pinpoint Tests PINPOINT TEST A: NO COMMUNICATION WITH THE REAR AIR SUSPENSION CONTROL MODULE Test Step A1 CHECK CIRCUIT 298 (VT/OG) FOR AN OPEN Key in OFF position. Disconnect: Rear Air Suspension Control Module C2131b. Key in ON position. Measure the voltage between rear air suspension control module C2131b pin 16, circuit 298 (VT/OG), harness side and ground. Is the voltage greater than 10 volts? Result / Action to Take Yes GO to A2. No REPAIR the circuit. REPEAT the self-test. A2 CHECK CIRCUIT 1053 (LB/PK) FOR AN OPEN Measure the voltage between rear air suspension control module C2131b pin 1 and pin 15, circuit 1053 (LB/PK), harness side and ground. Is the voltage greater than 10 volts? A3 CHECK CIRCUIT 676 (PK/OG) FOR AN OPEN Yes GO to A3. No REPAIR the circuit. REPEAT the self-test. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 8/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Yes Key in OFF position. REFER to Section 418- Measure the resistance between rear air suspension control module C2131b pin 6, 00. circuit 676 (PK/OG), harness side and ground. Is the resistance less than 5 ohms? No REPAIR the circuit. REPEAT the self-test. PINPOINT TEST B: UNABLE TO ENTER SELF-TEST Test Step Result / Action to Take B1 CHECK THE COMMUNICATIONS TO THE REAR AIR SUSPENSION CONTROL MODULE Yes Key in ON position. INSTALL a new air suspension control module. REFER to Air Turn the air suspension disable switch Suspension Module in this section. CLEAR the DTC(s). REPEAT the ON. self-test. Check the communication to the rear air suspension control module. No Does the scan tool communicate GO to Pinpoint Test A. with the air suspension control module? PINPOINT TEST C: DTC B1317/B1318 -- BATTERY VOLTAGE HIGH/LOW Test Step Result / Action to Take C1 CHECK BATTERY VOLTAGE NOTE: A recent jump start can cause these DTCs to set. Yes GO to C2. Measure the battery voltage between the positive and negative battery posts with the key ON engine OFF (KOEO) and with the engine running. No REFER to Section 414-00. Is the battery voltage between 10 and 13 volts with KOEO, and between 11 and 17 volts with the engine running? C2 CHECK CIRCUIT 298 (VT/OG) FOR AN OPEN https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 9/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Key in OFF position. Disconnect: Rear Air Suspension Control Module Yes GO to C3. C2131b. Key in ON position. Measure the voltage between rear air suspension No REPAIR the circuit. REPEAT the self-test. control module C2131b pin 16, circuit 298 (VT/OG), harness side and ground. Is the voltage greater than 10 volts and less than 17 volts? C3 CHECK CIRCUIT 1053 (LB/PK) FOR AN OPEN Measure the voltage between rear air suspension control module C2131b pin 1 and pin 15, circuit 1053 Yes GO to C4. (LB/PK), harness side and ground. No Is the voltage greater than 10 volts and less than 17 REPAIR the circuit. REPEAT the self-test. volts? C4 CHECK CIRCUIT 676 (VT/OG) FOR AN OPEN Key in OFF position. Disconnect: Rear Air Suspension Control Module C2131b . Measure the resistance between rear air suspension control module C2131b pin 6, circuit 676 (VT/OG), harness side and ground. Is the resistance less than 5 ohms? Yes INSTALL a new rear air suspension control module. REFER to Air Suspension Module in this section. REPEAT the self-test. No REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. PINPOINT TEST D: DTC B1566 -- DOOR AJAR CIRCUIT SHORT TO GROUND/DID NOT DETECT OPEN AND CLOSE DOOR SIGNALS D1 CHECK THE COURTESY LIGHTS Test Step Key in OFF position. Open a door. Did the courtesy lights illuminate? D2 CHECK THE DOOR SIGNAL Key in ON position. Monitor the door signal PID. Open and close a door. Does the door signal PID indicate correctly when the door is open and when closed? Result / Action to Take Yes GO to D2. No GO to D3. Yes The system is OK. No GO to D3. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 10/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic D3 CHECK CIRCUITS 1312 (LG/BK) FOR AN OPEN Disconnect the battery ground cable. Refer to Section 414-01. Disconnect: Air Suspension Control Module C2131b. Disconnect: Lighting Control Module C2145c. Measure the resistance between the air suspension control module C2131b pin 5, circuit 1312 (LG/BK) harness side and lighting control module (LCM) C2145c pin 4, harness side. Is the resistance less than 5 ohms? Yes GO to D4. No REPAIR the circuit. REPEAT the selftest. D4 CHECK CIRCUITS 1312 (LG/BK) FOR A SHORT TO POWER Key in ON position. Measure the voltage between the rear air suspension control module C2131b pin 5, circuit 1312 (LG/BK) and ground. Is voltage present? Yes REPAIR the circuit. REPEAT the selftest. No GO to D5. D5 CHECK CIRCUIT 1312 (LG/BK) FOR A SHORT TO GROUND Key in OFF position. Measure the resistance between the rear air suspension control module C2131b pin 5, circuit 1312 (LG/BK) and ground. Is the resistance greater than 10,000 ohms? Yes REFER to Section 417-02. No REPAIR the circuit. REPEAT the selftest.. PINPOINT TEST E: DTC C1724 -- AIR SUSPENSION HEIGHT SENSOR POWER CIRCUIT FAILURE Test Step E1 CHECK CIRCUIT 429 (VT/LG) FOR A SHORT TO POWER Disconnect: Air Suspension Control Module C2131a. Disconnect: Air Suspension Height Sensor C4043. Turn the air suspension switch to the OFF position. Key in ON position. Measure the voltage between rear air suspension control module C2131a pin 22, circuit 429 (VT/LG), harness side and ground. Is the voltage greater than 0 volt? Result / Action to Take Yes REPAIR circuit 429 (PK/LG). CLEAR the DTC. REPEAT the self-test. No GO to E2. E2 CHECK CIRCUIT 429 (VT/LG) FOR A SHORT TO GROUND https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2Ff... 11/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Yes Key in OFF position. GO to E3. Measure the resistance between rear air suspension control module C2131a pin 22, circuit 429 (VT/LG), harness side and ground. No REPAIR circuit 429 (PK/LG). CLEAR the DTC. Is the resistance greater than 10,000 ohms? REPEAT the self-test. E3 CHECK CIRCUIT 429 (VT/LG) FOR AN OPEN Yes Measure the resistance between rear air suspension control REPAIR the circuit. CLEAR the DTC. REPEAT module C2131a pin 22, circuit 429 (VT/LG), harness side the self-test. and air suspension height sensor C4043 pin 3, circuit 429 (VT/LG), harness side. Is the resistance greater than 5 ohms? No GO to E4. E4 CHECK THE REAR AIR SUSPENSION CONTROL MODULE OUTPUT Connect: Air Suspension Control Module C2131a. Key in ON position. Measure the voltage between air suspension height sensor C4043 pin 3, circuit 429 (VT/LG), harness side and ground. Is the voltage 5 volts? Yes INSTALL a new air suspension height sensor. REFER to Suspension Height Sensor -- Air in this section. CLEAR the DTC. REPEAT the selftest. No INSTALL a new air suspension control module. REFER to Air Suspension Module in this section. CLEAR the DTC(s). REPEAT the selftest. PINPOINT TEST F: DTC C1726 -- AIR SUSPENSION PNEUMATIC FAILURE NOTE: Repair all other DTCs before repairing DTC C1726. NOTE: It can be necessary to partially vent air from the rear air springs during this Pinpoint Test. Test Step F1 CHECK THE AIR SUSPENSION HEIGHT SENSOR MOUNTING Check the air suspension height sensor for correct installation at the upper and lower ball stud brackets. Check the air suspension height sensor mounting brackets for damage. Are the air suspension height sensor and mounting brackets OK? F2 CHECK THE AIR SUSPENSION HEIGHT SENSOR OPERATION Result / Action to Take Yes GO to F2. No REPAIR as necessary. CLEAR the DTC. REPEAT the self-test. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 12/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Disconnect the lower end of the air suspension height sensor. Key in ON position. Monitor the height sensor PID. While monitoring the height sensor PID display, slowly move the air suspension height sensor through its full range of motion. Does the height sensor PID indicate HIGH, TRIM and LOW? Yes GO to F3. No INSTALL a new air suspension height sensor. REFER to Suspension Height Sensor -- Air in this section. CLEAR the DTC. REPEAT the self-test. F3 VERIFY THAT THE REAR OF THE VEHICLE CAN BE RAISED Record the voltage level for the rear air suspension height sensor. Trigger the LR air spring solenoid ON active command. This will activate both the LR and RR air spring solenoids. Trigger the compressor ON. Allow the rear of the vehicle to raise for only 30 seconds. Does the rear of the vehicle raise and hold the new height? Yes TRIGGER air suspension control module active commands. GO to F4 . No TRIGGER air suspension control module active command OFF. GO to F5 . F4 VERIFY THAT THE REAR OF THE VEHICLE CAN BE LOWERED Trigger air suspension control module active command LR SOLENOID. This will activate both the LR and RR air spring solenoids. Trigger the compressor vent. Allow the rear to lower until the rear air suspension height sensor voltage reading matches the one recorded in Step F3 or until 30 seconds have passed. Does the rear of the vehicle lower? Yes RESET electronic ride height. REFER to Ride Height Adjustments in this section. CLEAR the DTCs. REPEAT the self-test. No GO to F7. F5 CHECK OPERATION OF THE AIR COMPRESSOR CAUTION: Do not allow the air compressor to run for more than three minutes. The air compressor could overheat and stop operation due to an internal temperature sensitive thermal breaker. Trigger air suspension control module active command: COMPRESSR ON. Does the air compressor run (slight buzzing noise from RF fender)? Yes TRIGGER air suspension control module active command COMPRESSR OFF. GO to F6 . No Go To Pinpoint Test L. F6 CHECK THE AIR COMPRESSOR PRESSURE OUTPUT https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 13/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Yes CAUTION: Do not allow the air compressor to run for more than three TRIGGER air suspension minutes. The air compressor could overheat and stop operation due to control module active an internal temperature sensitive thermal breaker. NOTE: If fluid is present command VENT OFF. GO to when disconnecting the air line, clear the air lines. Refer to Air Line Fluid Purge F9 . in this section. Check the compressor air drier for water or the air compressor for oil contamination. Disconnect the air line at the air drier. Connect an air gauge with a maximum reading of 1,723 kPa (205 psi) to the air drier using common fittings. Trigger air suspension control module active command: COMPRESSR ON. No INSTALL a new air suspension compressor. REFER to Air Suspension Compressor in this section Run the air compressor for only 30 seconds. Wait five minutes. Trigger air suspension control module active command: VENT ON. Does the compressor produce 896 kPa (130 psi) within 30 seconds and hold the developed pressure? F7 CHECK THE PNEUMATIC SYSTEM -- VENT THE AIR SPRINGS NOTE: If fluid is present when disconnecting the air line, clear the air lines. Refer to Air Line Fluid Purge. Check the air compressor drier for water or the air compressor for oil contamination. NOTE: The rear springs must be partially inflated in order to carry out this test. Add air as necessary. Disconnect the air compressor drier air line. Trigger the LR air spring solenoid ON active command. This will activate both the LR and RR air spring solenoids. Does the air vent from the air compressor drier air line? Yes Trigger the LR air spring solenoid OFF active command. GO to F9 . No Trigger the LR air spring solenoid OFF active command. GO to F8 . F8 CHECK THE PNEUMATIC SYSTEM -- AIR LINE NOTE: If fluid is present when disconnecting the air line, clear the air lines. Refer to Air Line Fluid Purge. Check the air compressor drier for water or the air compressor for oil. Disconnect the suspected rear air spring solenoid air line. Connect the vacuum tester to the air line and try to pull a vacuum. Can a vacuum be developed? F9 CHECK THE VENT SOLENOID OPERATION Yes REPAIR or INSTALL a new air line. CLEAR the DTC. REPEAT the self-test. No INSTALL a new air spring solenoid valve. REFER to Air Spring Solenoid Valve in this section. CLEAR the DTC. REPEAT the self-test. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 14/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Disconnect the air line at the drier. Connect the vacuum tester to the drier and try to pull a vacuum. Yes INSTALL a new air suspension control module. Trigger the vent solenoid ON active command. REFER to Air Suspension Try to pull a vacuum again. Module in this section. Can a vacuum be developed with the vent solenoid OFF active command REPEAT the self-test. and no vacuum developed with the vent solenoid ON active command? No If no vacuum can be developed with the vent solenoid OFF, GO to F10 . F10 CHECK THE AIR LINE AND CONNECTIONS Check the air line and connections between the vacuum tester and the air compressor. Are the air line and connections OK? If a vacuum can be developed with the vent solenoid OFF, GO to F11 . Yes INSTALL a new air compressor. REFER to Air Suspension Compressor in this section. CLEAR the DTC. REPEAT the self-test. No REPAIR the air line. CLEAR the DTC. REPEAT the selftest. F11 CHECK THE AIR COMPRESSOR DRIER Remove the air compressor drier. NOTE: Under normal operating conditions, the compressor drier should pull a vacuum and then slowly leak down. A drier is defective if it will not pull a vacuum or if it pulls a vacuum but fails to slowly leak down. Connect the vacuum tester to the air compressor drier and try to pull a vacuum. Can a vacuum be developed, followed by a slow leak down? Yes INSTALL a new air compressor. REFER to Air Suspension Compressor in this section. CLEAR the DTC. REPEAT the self-test. No INSTALL a new air compressor drier. CLEAR the DTC. REPEAT the self-test. PINPOINT TEST G: DTC C1760 -- AIR SUSPENSION REAR HEIGHT SENSOR HIGH SIGNAL CIRCUIT FAILURE G1 VERIFY THE DTC Test Step Result / Action to Take https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 15/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Carry out the rear air suspension control module On-Demand self-test. Is DTC C1760 present? Yes GO to G2. No If a different DTC is retrieved, REFER to rear air suspension control Module DTC index. G2 CHECK THE HEIGHT SENSOR POWER Key in OFF position. Turn the air suspension switch OFF. Disconnect: Air Suspension Height Sensor C4043. Turn the air suspension switch ON. Key in ON position. Monitor the air suspension height sensor PID. Measure the voltage between air suspension height sensor C4043 pin 1, circuit 432 (BK/PK) and pin 3, circuit 429 (VT/LG), harness side. Is the voltage approximately 5 volts? Yes GO to G4. No If the voltage is less than 5 volts, GO to G3 . If the voltage is greater than 5 volts, REPAIR circuit 429 (VT/LG). CLEAR the DTC. REPEAT the self-test. G3 CHECK THE AIR SUSPENSION HEIGHT SENSOR GROUND NOTE: Use the battery negative terminal as ground for this test. Measure the resistance between the air suspension height sensor C4043 pin 1, circuit 432 (BK/PK), harness side and ground. Is the resistance less than 5 ohms? Yes REPAIR circuit 429 (VT/LG). CLEAR the DTC. REPEAT the self-test. No REPAIR circuit 432 (BK/PK) and circuit 676 (PK/OG). CLEAR the DTC. REPEAT the self-test. G4 CHECK CIRCUIT 427 (PK/BK) FOR AN OPEN AND A SHORT TO GROUND Key in OFF position. Turn the air suspension switch OFF. Disconnect: Rear Air Suspension Control module C2131a. Measure the resistance between the air suspension height sensor C4043 pin 2, circuit 427 (PK/BK), harness side and rear air suspension control module C2131a pin 12, circuit 427 (PK/BK), harness side; and between air suspension height sensor C4043 pin 2, circuit 427 (PK/BK), harness side and ground. Is the resistance less than 5 ohms between the air suspension height sensor and the rear air suspension control module, and greater than 10,000 ohms between the air suspension height sensor and ground? Yes RECONNECT the system. GO to G5 . No REPAIR circuit 427 (PK/BK). CLEAR the DTC. REPEAT the self-test. G5 CHECK FOR AN INTERMITTENT FAULT https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 16/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Connect: Rear Air Suspension Control Module C2131a. Turn the air suspension switch ON. Key in ON position. Yes REPAIR circuits 427 (PK/BK), 432 (BK/PK) and 429 (VT/LG) as necessary. CLEAR the DTC. Monitor the rear air suspension control module PID. REPEAT the self-test. Monitor the PID display while wiggling the wire harness between the air suspension rear height sensor and the air suspension control module. No Does the air suspension rear height sensor voltage ever indicate less than 0.2 volt or greater than 5 volts? INSTALL a new air suspension height sensor. REFER to Suspension Height Sensor -- Air in this section. CLEAR the DTC. REPEAT the self-test. PINPOINT TEST H: DTC C1770 -- AIR SUSPENSION VENT SOLENOID OUTPUT CIRCUIT FAILURE Test Step Result / Action to Take H1 CHECK CIRCUIT 421 (PK) FOR A SHORT TO POWER Key in OFF position. Disconnect: Rear Air Suspension Control Module C2131a. Yes REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. Disconnect: Air Compressor C1179. No Key in ON position. GO to H2. Measure the voltage between the rear air suspension control module C2131a pin 24, circuit 421 (PK), harness side and ground. Is the voltage greater than 0 volt? H2 CHECK CIRCUIT 421 (PK) FOR A SHORT TO GROUND Key in OFF position. Measure the resistance between rear air suspension Yes GO to H3. control module C2131a pin 24, circuit 421 (PK), harness No side and ground. REPAIR circuit 421 (PK). CLEAR the DTC. Is the resistance greater than 10,000 ohms? REPEAT the self-test. H3 CHECK CIRCUIT 421 (PK) FOR AN OPEN Measure the resistance between the rear air suspension control module C2131a pin 24, circuit 421 (PK) and air compressor C1179 pin 1, circuit 421 (PK), harness side. Is the resistance less than 5 ohms? Yes GO to H4. No REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. H4 CHECK CIRCUIT 57 (BK) FOR AN OPEN https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 17/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Measure the resistance between the air compressor C1179 pin 2, circuit 57 (BK), harness side and ground. Is the resistance greater than 5 ohms? Yes REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. No GO to H5. H5 CHECK THE AIR COMPRESSOR VENT SOLENOID Measure the resistance between the air compressor C1179 pin 2 and pin 3, component side. Is the resistance between 15 and 25 ohms? Yes INSTALL a new air suspension control module. REFER to Air Suspension Module in this section. CLEAR the DTC(s). REPEAT the self-test. No INSTALL a new air compressor. REFER to Air Suspension Compressor in this section. CLEAR the DTC. REPEAT the self-test. PINPOINT TEST I: DTCS C1790/C1795 -- LR/RR AIR SUSPENSION AIR SPRING SOLENOID OUTPUT CIRCUIT FAILURE Test Step I1 CHECK CIRCUITS 1114 (BN/PK) AND 1115 (TN/WH) FOR AN OPEN Key in OFF position. Disconnect: Air Suspension Control Module C2131a. Disconnect: Air Suspension LR Air Spring Solenoid C4044. Disconnect: Air Suspension RR Air Spring Solenoid C4045. Measure the resistance between the air suspension control module C2131a pin 13, circuit 1114 (BN/PK) harness side and LR air spring solenoid C4044 pin 1, harness side; and between air suspension control module C2131a pin 25, circuit 1115 (TN/WH) harness side and RR air spring solenoid C4045 pins 1, harness side. Are the resistances less than 5 ohms? Result / Action to Take Yes GO to I2. No REPAIR the circuit in question. CLEAR the DTC(s). REPEAT the self-test. I2 CHECK CIRCUITS 1114 (BN/PK) AND 1115 (TN/WH) FOR A SHORT TO POWER Yes Key in ON position. REPAIR the affected circuit(s). Measure the voltage between the rear air suspension control module pin CLEAR the DTC(s). REPEAT the 13, circuit 1114 (BN/PK) and ground; and between the rear air suspension self-test. control module pin 25, circuit 1115 (TN/WH) and ground. Is voltage present? No GO to I3. I3 CHECK CIRCUITS 1114 (BN/PK) AND 1115 (TN/WH) FOR A SHORT TO GROUND https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 18/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Key in OFF position. Measure the resistance between the rear air suspension control module pin 13, circuit 1114 (BN/PK) and ground; and between the rear air suspension control module pin 25, circuit 1115 (TN/WH) and ground. Is the resistance greater than 10,000 ohms? Yes GO to I4. No REPAIR the affected circuit(s). CLEAR the DTC(s). REPEAT the self-test. I4 CHECK CIRCUIT 57 (BK) FOR AN OPEN Key in OFF position. Measure the resistance between the LR air suspension solenoid C4044 pin 2, circuit 57 (BK) and ground; and between the RR air suspension solenoid C4045 pin 2, circuit 57 (BK) and ground. Is the resistance less than 5 ohms? Yes GO to I5. No REPAIR the affected circuit(s). CLEAR the DTC(s). REPEAT the self-test. I5 CHECK THE LR AND RR AIR SPRING SOLENOIDS Key in OFF position. Measure the resistance between the LR air suspension solenoid C4044 pins 1 and 2; and between the RR air suspension solenoid C4045 pins 1 and 2. Are the resistances between 10 and 17 ohms? Yes INSTALL a new air suspension control module. REFER to Air Suspension Module in this section. CLEAR the DTC(s). REPEAT the self-test. No INSTALL a new LR or RR air spring solenoid. REFER to Air Spring Solenoid Valve in this section. CLEAR the DTC(s). REPEAT the self-test. PINPOINT TEST J: DTC C1830 -- AIR COMPRESSOR RELAY CIRCUIT FAILURE Test Step J1 CHECK THE AIR COMPRESSOR RELAY CONNECTOR Key in OFF position. Disconnect: Air Compressor Relay. Check the air compressor relay connector pins and terminals for corrosion, bent or broken pins, moisture or other damage. Is the air compressor relay connector OK? Result / Action to Take Yes GO to J2. No REPAIR as necessary. CLEAR the DTC. REPEAT the self-test. J2 CHECK THE POWER TO THE AIR SUSPENSION RELAY https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 19/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Measure the voltage between air compressor relay pin 1 and pin 3, circuit 1053 (LB/PK), harness side and ground. Are the voltages greater than 10 volts? Yes GO to J3. No REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. J3 CHECK CIRCUIT 420 (DB/YE) FOR AN OPEN Key in OFF position. Disconnect: Air Suspension Control Module C2131b. Measure the resistance between rear air suspension control module C2131b pin 23, circuit 420 (DB/YE), harness side and air compressor relay pin 2, circuit 420 (DB/YE) harness side. Is the resistance less than 5 ohms? Yes GO to J4. No REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. J4 CHECK CIRCUIT 420 (DB/YE) FOR A SHORT TO GROUND Measure the resistance between rear air suspension control module C2131b pin 23, circuit 420 (DB/YE), harness side and ground. Is the resistance greater than 10,000 ohms? Yes GO to J5. No REPAIR the circuit. CLEAR the DTC. REPEAT the self-test. J5 CHECK THE AIR COMPRESSOR RELAY COIL FOR AN OPEN Measure the resistance between air compressor relay pin 1 and pin 2 (component side). Is the resistance greater than 10,000 ohms? Yes INSTALL a new air compressor relay. CLEAR the DTC. REPEAT the self-test. No INSTALL a new rear air suspension control module. REFER to Air Suspension Module in this section. REPEAT the self-test. PINPOINT TEST K: DTC C1840 -- AIR SUSPENSION SWITCH CIRCUIT FAILURE Test Step K1 CHECK THE AIR SUSPENSION SWITCH VOLTAGE Key in ON position. Disconnect: Air Suspension Switch C4087. Measure the voltage between air suspension switch C4087-1, circuit 429 (VT/LG) harness side and ground. Is the voltage 5 volts? Result / Action to Take Yes GO to K2. No GO to K4. K2 CHECK CIRCUIT 418 (DG/YE) FOR AN OPEN https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 20/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Disconnect: Air Suspension Module C2131a. Disconnect: Air Suspension Module C2131b. Measure the resistance between air suspension switch C4087-3, circuit 418 (DG/YE) harness side and air suspension module C2131b-2, circuit 418 (DG/YE), harness side. Is the resistance less than 5 ohms? Yes GO to K3. No REPAIR circuit 418 (DG/YE). CLEAR the DTCs. REPEAT the self-test. K3 CHECK CIRCUIT 418 (DG/YE) FOR A SHORT TO GROUND Measure the resistance between air suspension module C2131b-2, circuit 418 (DG/YE), harness side and ground. Is the resistance greater than 10,000 ohms? Yes GO to K6. No REPAIR circuit 418 (DG/YE). CLEAR the DTCs. REPEAT the self-test. K4 CHECK CIRCUIT 429 (VT/LG) FOR AN OPEN Measure the resistance between air suspension switch C4087-1, circuit 429 (VT/LG) harness side and air suspension module C2131a-22, circuit 429 (VT/LG). Is the resistance less than 5 ohms? Yes GO to K5. No REPAIR circuit 429 (VT/LG). CLEAR the DTCs. REPEAT the self-test. K5 CHECK CIRCUIT 429 (VT/LG) FOR A SHORT TO GROUND Measure the resistance between air suspension module C2131a-22, circuit 429 (VT/LG), harness side and ground. Is the resistance greater than 10,000 ohms? Yes GO to K6. No REPAIR circuit 429 (VT/LG). CLEAR the DTCs. REPEAT the self-test. K6 CHECK THE AIR SUSPENSION SWITCH Connect: Air Suspension Module C2131a. Connect: Air Suspension Module C2131b. Push the air suspension switch to the ON position. Measure the resistance between air suspension switch pin 1, component side and pin 2, component side. Is the resistance less than 5 ohms? Yes GO to K7. No INSTALL a new air suspension switch. REFER to Air Suspension Switch in this section. CLEAR the DTCs. REPEAT the self-test. K7 VERIFY THE AIR SUSPENSION MODULE CONNECTIONS https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 21/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Check air suspension module connectors C2131a and C2131b for damage or loose connections. Are the module connections OK? Yes INSTALL a new air suspension module. REFER to Air Suspension Module in this section. CLEAR the DTCs. REPEAT the self-test. No REPAIR the air suspension module connectors. CLEAR the DTCs. REPEAT the self-test. PINPOINT TEST L: THE COMPRESSOR IS INOPERATIVE Test Step L1 CHECK THE AIR COMPRESSOR RELAY Key in OFF position. Disconnect: Air Compressor Relay. Carry out the relay component test. Refer to Wiring Diagrams Cell 149 for schematic and connector information. Does the relay pass the component test? L2 CHECK CIRCUIT 1053 (LB/PK) FOR AN OPEN Key in OFF position. Disconnect: Air Compressor Relay . Measure the voltage between air compressor relay pin 3, circuit 1053 (LB/PK), harness side and ground. Result / Action to Take Yes GO to L2. No INSTALL a new air compressor relay. REPEAT the self-test. Yes GO to L3. No REPAIR the circuit. REPEAT the self-test. Is the voltage greater than 10 volts? L3 CHECK CIRCUIT 538 (GY/RD) FOR AN OPEN https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 22/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic Disconnect: Air Compressor C1179. Measure the resistance between air compressor relay pin 5, circuit 538 (GY/RD), harness side and air compressor C1179 pin 3, circuit 538 (GY/RD), harness side. Yes GO to L4. No REPAIR the circuit. REPEAT the self-test. Is the resistance less than 5 ohms? L4 CHECK CIRCUIT 57 (BK) FOR AN OPEN Yes Measure the resistance between air compressor C1179 pin 4, GO to L5. circuit 57 (BK), harness side and ground. No REPAIR the circuit. REPEAT the self-test. Is the resistance less than 5 ohms? L5 CHECK CIRCUIT 538 (GY/RD) FOR VOLTAGE Key in ON position. Trigger the air compressor ON active command. Measure the voltage between air compressor C1179 pin 3, circuit 538 (GY/RD), harness side and ground. Is the voltage greater than 10 volts? Yes INSTALL a new air compressor. REFER to Air Suspension Compressor in this section. REPEAT the self-test. No REPAIR circuit 538 (GY/RD). REPEAT the self-test. PINPOINT TEST M: THE AIR COMPRESSOR CONTINUOUSLY CYCLES WITH THE IGNITION SWITCH IN THE OFF POSITION AND NO DTC IS SET Test Step M1 CHECK FOR MODULE ACTIVITY Result / Action to Take https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 23/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic NOTE: The rear air suspension control module is powered for approximately 60 minutes after the ignition switch is placed in the OFF position. During this time, the air suspension will correct for vehicle weight by raising the vehicle. Key in OFF position. Turn the air suspension switch to the OFF position. Verify the air compressor still cycles 60 minutes after the ignition switch is placed in the OFF position. Does the air compressor still cycle continuously after the air suspension module is disabled? Yes GO to M2. No The system is OK. M2 CHECK THE REAR AIR SUSPENSION CONTROL MODULE Disconnect: Rear Air Suspension Control Module C2131a. Does the air compressor still cycle? M3 CHECK CIRCUIT 538 (GY/RD) FOR A SHORT TO POWER Disconnect: Air Compressor Relay. Does the air compressor still cycle? Yes GO to M3. No INSTALL a new rear air suspension control module. REFER to Air Suspension Module in this section. REPEAT the self-test. Yes REPAIR Circuit 538 (GY/RD). REPEAT the self-test. No INSTALL a new air compressor relay. REPEAT the self-test. https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 24/25 2/20/2021 Vehicle Dynamic Suspension - Diagnosis and Testing · 2003 Ford Crown Victoria · MotoLogic https://www.motologic.com/car/f123cfd0-ca4d-012b-1090-fbb1677812c1/article/681c28b0-4418-012a-7060-fd437078c5d3?returnPath=%2Fcar%2F... 25/25Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.182 Safari/537.36 Skia/PDF m88