Electrical System - Transmission Control

9.14.6 Transmission Shift Control Switch

a. Travel Select Lever

The transmission shift control switch, also known as the travel select lever [1], is located on the left side of the steering column. This switch has three positions: (F) FORWARD [2] (fully up), (N) NEUTRAL [3] (center), and (R) REVERSE [4] (fully down). The engine can only be started when the switch or lever is in the (N) NEUTRAL [3] position.

Diagram Description: A depiction of the steering column area showing the travel select lever [1] with indicator markings for FORWARD [2], NEUTRAL [3], and REVERSE [4]. The lever is shown in the NEUTRAL position.

Moving the lever [1] actuates electrical contacts within the switch, directing electricity to the appropriate relays and then to the transmission shift solenoids.

To change travel selections, grasp the lever, pull it towards the steering wheel, and then move it up or down to the desired selection: (F) FORWARD [2] or (R) REVERSE [4].

When the switch is shifted to the (R) REVERSE [4] position, a back-up alarm will sound automatically.

Refer to circuit diagrams in Section 9.8, "Transmission Gear Selection Troubleshooting," and Section 9.14.7, a. "Travel Select Lever and Wiring Harness Testing."

For removal and installation instructions, refer to Section 4.3.2, c. "Transmission Travel and Gear Select Lever Removal," and Section 4.3.2, d. "Transmission Travel and Gear Select Lever Installation."

b. Gear Select Lever

The gear select lever [5] is integrated into the transmission shift control switch (travel select lever). It features a twist-grip handle with four positions.

Diagram Description: A close-up view of the gear select lever [5] with its twist-grip handle, showing four distinct positions labeled 1st, 2nd, 3rd, and 4th.

The vehicle is equipped with four forward gears and three reverse gears. First gear provides the highest torque and pulling power, while higher-numbered gears are used for increasing vehicle travel speed.

For removal and installation instructions, refer to Section 4.3.2, c. "Transmission Travel and Gear Select Lever Removal," and Section 4.3.2, d. "Transmission Travel and Gear Select Lever Installation."

Model Information: Model 8042, 10042, 10054 Legacy Rev. 10/03

9.14.7 Transmission Solenoid Valves

The transmission utilizes six solenoids for shifting. Three solenoid valves (Y1, Y2, and Y3) are housed in an UPPER spool-type solenoid cartridge assembly (valve body) [6].

Diagram Description: An illustration showing the upper solenoid cartridge assembly labeled [6].

The remaining three solenoid valves (Y4, Y5, and Y6) are located in the LOWER spool-type solenoid cartridge assembly (valve body) [7]. While all 12-volt solenoid coils are identical, their internal wiring differs, enabling the actuation of various transmission clutches based on input from the transmission shift control switch (travel select lever).

Diagram Description: An illustration showing the lower solenoid cartridge assembly labeled [7].

By selecting a position on the transmission shift control switch (travel select lever), a specific combination of solenoids is activated, which in turn engages a set of internal clutches. Refer to Section 9.14.7, a. "Travel Select Lever and Wiring Harness Testing," and Section 9.14.7, b. "Upper and Lower Transmission Valve Body Solenoid Testing."

If the transmission is not shifting correctly, the transmission shift control switch (travel select lever), wiring harness, or transmission shift solenoids should be inspected to identify the defective component. Detailed information for determining which travel position and corresponding component is malfunctioning can be found by consulting the circuit diagrams in Section 9.8, "Transmission Gear Selection Troubleshooting." Replace any defective component.

Model Information: Model 8042, 10042, 10054 Legacy Rev. 10/03

9.14.7.a Travel Select Lever and Wiring Harness Testing

Note: An assistant is required to operate the travel select lever during this test.

1. Remove the plug from the UPPER [1] and [3] and LOWER [2] and [5] transmission solenoid valve bodies. Turn the ignition key switch to the RUN position.

Diagram Description: An illustration of the transmission showing the locations of the upper and lower solenoid valve bodies.

Note: For solenoid testing, the park brake switch must be in the OFF position.

2. Have an assistant place the travel select lever in the position that is not functioning correctly.
3. Check the harness side pin connections with a Digital Multimeter (DMM) for battery voltage corresponding to the selected direction and gear. Place the negative (-) lead on pin 7 (ground) [4] or [6] and the positive (+) lead on the pin to be tested. Test for battery voltage.

If battery voltage is not present on any of the tested pins, the wiring harness is suspect and should be replaced.

If battery voltage is present, the harness is functioning properly.

Diagram Description: A diagram showing the pin configuration of the transmission solenoid valve connector, with pins labeled [1] through [16]. Also shows labels for solenoids Y1, Y2, Y3, Y4, Y5, Y6.

Solenoid Activation Chart

The following chart indicates which solenoids are active for each selection of the transmission shift control switch (travel select lever) and gear select position.

Model Information: Model 8042, 10042, 10054 Legacy Rev. 10/03

9.14.7.b Upper and Lower Transmission Valve Body Solenoid Testing

Inspect the solenoid connector plugs [7] and [12]. Using the chart below, test each pin connection on the upper transmission valve body connector for continuity and shorting. Each solenoid should exhibit between 25.0 and 30.0 ohms of resistance when tested with an ohm/volt meter. Replace any defective solenoid valve. Refer to Section 9.14.7, c. "Transmission Upper Valve Body Solenoid Removal."

Diagram Description: A diagram showing the pin configuration of the upper transmission valve body connector, with pins labeled [1] through [16].

Diagram Description: A diagram showing the pin configuration of the lower transmission valve body connector, with pins labeled [1] through [16].

Solenoid Pinout Table

Note: All six solenoids within both upper and lower solenoid valve body housings are of the same design.

9.14.7.c Transmission Upper Valve Body Solenoid Removal

Note: Before removing the valve body protective cover, clean the area around the housing to prevent contamination.

1. If the vehicle has one battery, disconnect the negative (-) battery cable at the negative (-) battery terminal [17]. If the vehicle has dual batteries, disconnect both negative battery cables from both negative (-) battery terminals [18].

Diagram Description: Illustrations showing battery terminal disconnect procedures for single and dual battery systems, with terminals labeled [17] and [18].

2. Remove the six capscrews [1], four hex-head capscrews [2], ten lockwashers [3] and [4], and the protective cover plate [5] secured over the transmission solenoid cartridge valve [6]. Inspect the protective cover gasket [7]; replace if torn or missing.

Diagram Description: An exploded view of the upper valve body cover assembly, showing components like capscrews [1], [2], lockwashers [3], [4], cover plate [5], solenoid valve [6], and gasket [7]. Also shows spring [14].

3. Disconnect the internal wire connector [8] from the solenoid valve that is being removed. Label the internal wire connections if removing more than one solenoid valve.
4. Remove the solenoid capscrew [9], retaining plate [10], and flat washer [11] securing the solenoid valve [6] to the transmission.
5. Remove the solenoid valve [6] and replace.

9.14.7.d Transmission Upper Valve Body Solenoid Installation

Note: When installing the solenoid valve into the valve body, position the solenoid valve wires so that they do not interfere with the protective cover plate.

1. Install the flat washer [11] and solenoid valve [6] along with the retaining plate [10]. Connect the internal wire connector to the solenoid. Ensure that the claw side [12] of the retaining plate is facing down toward the valve body surface [13].
2. Install the solenoid capscrew [9] and torque to 53 lb-in (6 Nm).
3. Install the protective cover gasket [7] on the valve body. Position the protective cover plate [5] over the gasket. Install six lockwashers [3] and capscrews [1], and tighten until the valve body spring [14] (upper valve body only) is compressed and the cover plate sits flush over the gasket.
4. Install the four lockwashers [4] and four capscrews [2]. Torque to 84 lb-in (9.5 Nm).
5. If the vehicle has one battery, connect the negative (-) battery cable to the negative (-) battery terminal [15]. If the vehicle has dual batteries, connect both negative battery cables to both negative (-) battery terminals [16].

Diagram Description: Illustrations showing battery terminal connections for single [15] and dual [16] battery systems.

6. Test the operation of the transmission. Put the transmission through its entire range of gears (speeds) in both (F) FORWARD and (R) REVERSE, and check that the transmission also shifts into (N) NEUTRAL.
7. Verify that each function works properly and that the transmission does not engage when in (N) NEUTRAL.

For further information, refer to the Transmission Service Manual, Model ZF 4 WG-98 TC, P/N 8990455 (ZF P/N 5871 135 002).

9.14.7.e Transmission Lower Valve Body Solenoid Removal

Note: In order to service the lower valve body housing, the upper valve body housing MUST be removed to allow access to the lower housing protective cover. The area around the upper and lower valve body housing must be thoroughly cleaned to avoid contamination of internal transmission components.

1. If the vehicle has one battery, disconnect the negative (-) battery cable at the negative (-) battery terminal [15]. If the vehicle has dual batteries, disconnect both negative battery cables from both negative (-) battery terminals [16].

2. Thoroughly clean the area around the upper and lower valve body housing.
3. Remove screws securing the upper valve housing to the transmission.
4. Remove upper valve body housing from transmission, and set aside in a clean area, free of dirt, grease and oil.
5. Remove the upper valve housing flat gasket.
6. Remove the nine lower valve body protective cover screws [17], lockwashers [18], protective cover [19], and gasket [20].

Diagram Description: An exploded view of the lower valve body cover assembly, showing components like protective cover screws [17], lockwashers [18], protective cover [19], and gasket [20]. Also shows internal components like wire connector [21], solenoid capscrew [22], retaining plate [23], and solenoid valve [24].

7. Disconnect the internal wire connector [21] from the solenoid valve that is being removed. Label the internal wire connections if removing more than one solenoid valve.
8. Remove the solenoid capscrew [22] and retaining plate [23], securing the solenoid valve [24] to the transmission.
9. Remove the solenoid valve [24] and replace.

9.14.7.f Transmission Lower Valve Body Solenoid Installation

Note: When installing the solenoid valve into the valve body, position the solenoid valve wires so they do not interfere with the protective cover plate.

1. Install the solenoid valve [24] and retaining plate [23]. Connect the internal wire connector [21] to the solenoid. Ensure that the claw side of the retaining plate [23] is facing down toward the valve body surface.
2. Install the solenoid capscrew [22] and torque to 53 lb-in (6 Nm).
3. Install the protective cover gasket [20] onto the valve body. Position the protective cover [19] over the gasket. Install lockwashers [18] and capscrews [17], and tighten until the cover plate is compressed and it sits flush over the gasket. Torque to 84 lb-in (9.5 Nm).
4. Install the upper transmission valve body gasket and upper valve body assembly to transmission.
5. Install the lockwashers and capscrews, and torque screws to 84 lb-in (9.5 Nm).
6. If the vehicle has one battery, connect the negative (-) battery cable to the negative (-) battery terminal [15]. If the vehicle has dual batteries, connect both negative battery cables to both negative (-) battery terminals [16].

7. Test the operation of the transmission. Put the transmission through its entire range of gears (speeds) in both (F) FORWARD and (R) REVERSE, and check that the transmission also shifts into (N) NEUTRAL.
8. Verify that each function works properly and that the transmission does not engage when in (N) NEUTRAL.

For further information, refer to the Transmission Service Manual, Model ZF 4 WG-98 TC, P/N 8990455 (ZF P/N 5871 135 002).

Model Information: Model 8042, 10042, 10054 Legacy Rev. 10/03