1NZ-FE Ignition System

Parts Location

This section illustrates the location of key ignition system components on the 1NZ-FE engine and within the vehicle.

Key Components:

• ECM [Engine Control Module]: Located in the engine bay.
• Ignition Coil No. 1: Mounted on the engine.
• Spark Plug: Located within the engine cylinders, accessed via ignition coils.
• Crankshaft Position Sensor: Mounted on the engine.
• Camshaft Position Sensor: Mounted on the engine.

System Diagram

The ignition system diagram shows the electrical connections between the main power sources, control module, and ignition components.

Main Components and Connections:

• Battery: The primary power source.
• Fuses: Protected by a 60A [MAIN] fuse and a 15A [AM2] fuse.
• Ignition Switch: Controls power to the [AM2] and [IG2] circuits.
• [IG2] Relay: Activated by the ignition switch to supply power.
• ECM [Engine Control Module]: Receives power ([B+]), ignition timing signals ([IGT]), and ground ([GND]). It outputs [IGT] signals to each ignition coil.
• Ignition Coils (No. 1 to No. 4): Each coil receives [B+], [IGT], and [GND]. They also provide an [IGF] (Ignition Feedback) signal to the ECM.

Sensor Connections

This diagram details the sensor inputs to the ECM.

• Crankshaft Position Sensor: Connected to the ECM via shielded cables, providing [NE+] and [NE-] signals.
• Camshaft Position Sensor: Connected to the ECM via a shielded cable, providing a [G24] signal.
• A ground point ([C1]) is indicated.

On-Vehicle Inspection

Procedures for inspecting the ignition system while installed on the vehicle.

HINT: Temperature definitions: Cold (approx. -10 to 50 °C / 14 to 122 °F), Hot (approx. 50 to 100 °C / 122 to 212 °F).

1. Inspect Ignition Coil and Spark Test

NOTICE: If a Diagnostic Trouble Code ([DTC]) is present, follow the procedure for that specific code.

(b) Check for Sparks:

1. Remove Cylinder Head Cover No. 2 (Refer to page IG-9).
2. Remove the 4 ignition coils (Refer to page IG-9).
3. Using a 16 mm (0.63 in) plug wrench, remove the 4 spark plugs.
4. Install spark plugs onto each ignition coil and connect the ignition coil connectors.
5. Disconnect the 4 injector connectors.
6. [Ground the spark plugs].
7. [Check for sparks] while the engine is being cranked.

NOTICE:

• Ensure the spark plug is grounded during the test.
• Replace ignition coils that have sustained physical impact.
• Do not crank the engine for more than 2 seconds continuously.

If no sparks occur, proceed with the following:

(c) Perform Spark Test Procedure:

1. Verify the wire harness side connector of the ignition coil with igniter is securely connected.

   Result	Proceed to
   [NG]	[Connect securely]
   [OK]	[Go to next step]

2. Perform a spark test on each ignition coil with igniter:
   1. Replace the ignition coil with a known functioning one.
   2. Perform the spark test again.

   Result	Proceed to
   [OK]	[Replace ignition coil with igniter]
   [NG]	[Go to next step]

(3) Check Power Supply:

1. Turn the engine switch ON.
2. Verify battery voltage is applied to the positive (+) terminal of the ignition coil (Refer to page ES-172).

   Result	Proceed to
   [NG]	[Check wiring between ignition switch and ignition coil with igniter]
   [OK]	[Go to next step]

(4) Check Camshaft Position Sensor Resistance:

Standard resistance:

(5) Check Crankshaft Position Sensor Resistance:

Standard resistance:

(6) Check [IGT] from ECM: (Refer to page ES-172)

(d) Connect the 4 injector connectors.

(e) Install the 4 spark plugs using a 16 mm (0.63 in) plug wrench.

Torque: 18 N*m (184 kgf*cm, 13 ft.*lbf)

(f) Install the 4 ignition coils (Refer to page IG-9).

(g) Install Cylinder Head Cover No. 2 (Refer to page IG-10).

2. Inspect Spark Plug

NOTICE: Do not use a wire brush for cleaning.

(a) Check Electrode:

1. Using a megaohmmeter, [Measure insulation resistance].
2. Standard resistance: 10 MΩ or more.

HINT:

• If the result is not as specified, clean the spark plug with a spark plug cleaner and measure resistance again.
• If a megaohmmeter is unavailable, perform the following simple inspection:

(b) Alternative Inspection Method:

1. Quickly accelerate the engine to 4,000 rpm 5 times.
2. Remove the spark plug.
3. [Visually check] the spark plug. If the electrode is dry, it is functioning properly. If damp, proceed to the next step.

(c) Check for Damage: Inspect the spark plug for any damage to its thread and insulator. If damaged, replace the spark plug.

Recommended Spark Plugs:

(d) Check Electrode Gap:

• Maximum electrode gap for used spark plug: 1.3 mm (0.051 in.). If the gap exceeds this, replace the spark plug.
• Electrode gap for new spark plug: 1.0 to 1.1 mm (0.039 to 0.043 in.).

(e) [Clean the spark plug]: If the electrode shows traces of wet carbon, clean it with a spark plug cleaner and dry it.

• Air pressure: 588 kPa (6 kgf/cm², 85 psi).
• Duration: 20 seconds or less.

HINT: Use spark plug cleaner only when the electrode is free of oil. If oil is present, clean with gasoline first before using the spark plug cleaner.

Ignition Coil Components

This section details the components related to the ignition coils and their installation.

Cylinder Head Cover No. 2:

The Cylinder Head Cover No. 2 is shown installed on the engine. The specified torque for its fasteners is 7.0 N*m (71 kgf*cm, 62 in.*lbf).

Ignition Coil No. 1:

Ignition Coil No. 1 is shown installed. The specified torque for its mounting bolt is 9.0 N*m (92 kgf*cm, 80 in.*lbf).

Removal

Procedures for removing ignition system components.

1. Disconnect Cable from Negative Battery Terminal.
2. Remove Cylinder Head Cover No. 2:
   • Remove the 4 nuts securing the cover.
3. Remove Ignition Coil No. 1:
   • Disconnect the 4 ignition coil connectors.
   • Remove the 4 bolts securing the 4 ignition coils.

Installation

Procedures for installing ignition system components.

1. Install Ignition Coil No. 1:
   • Install the 4 ignition coils using the 4 bolts.
   • Torque: 9.0 N*m (92 kgf*cm, 80 in.*lbf).
   • Connect the 4 ignition coil connectors.
2. Install Cylinder Head Cover No. 2:
   • Tighten the 2 'A' nuts, then the 2 'B' nuts.
   • Torque: 7.0 N*m (71 kgf*cm, 62 in.*lbf).
3. Connect Cable to Negative Battery Terminal.
   • Torque: 5.4 N*m (55 kgf*cm, 48 in.*lbf).