Component Tests and General Diagnostics

CIRCUIT DESCRIPTION
There are two separate ignition module assemblies, one for each bank of cylinders. Each assembly contains an ignition control (IC) module and four ignition coils. Each IC module consists of the following circuits:
^ Ignition 1 voltage
^ Ground
^ IC timing low reference
^ IC circuits for cylinders 1-8

Each ignition coil connects directly to its spark plug via a short boot. The IC circuits transmit timing pulses from the powertrain control module (PCM) to the IC modules, which triggers the coils to fire the plugs in the correct sequence. The PCM monitors each IC circuit for improper voltage levels.

DIAGNOSTIC AIDS
When servicing the ignition system components, use the following recommended procedures:
^ If a boot remains attached to a coil or spark plug, twist the boot prior to removal.
^ Inspect the boot for a missing or damaged internal spring.
^ Do not re-install any component that has visible signs of damage.
^ Install the boots onto the coils (until bottomed out). Then install the assembly onto the spark plugs. If this is not possible due to space limitations, start the boots onto the spark plugs and then install the coil assembly as straight down onto the plugs as possible.
^ Ensure that the boots are installed right side up.
^ Lift the module beauty cover at the end opposite the module to remove.
^ Repair a torn perimeter seal with RTV sealant.
^ Adhere to the torque specifications when installing the coil cassette to the cam cover and the ignition module to the coil cassette.

A suspected ignition system misfire may actually be a condition other than the secondary ignition system. Verify the proper operation of the following items:
^ Fuel System
- Fuel Injector Balance Test with Special Tool or Fuel Injector Balance Test with Tech 2.
- Fuel Injector Coil Test.
^ Engine Mechanical
Test for base engine conditions that could produce an engine misfire. Refer to Symptoms-Engine. Symptom Related Diagnostic Procedures

TEST DESCRIPTION

Steps 1-7:

Steps 8-13:

Steps 14-24:

The numbers below refer to the step numbers on the diagnostic table.
7. An ignition coil, boots or spark plugs may misfire only when moisture is present. Although difficult to test on this engine, selectively wetting down parts of the system and monitoring for misfire, may isolate an intermittent condition. If moisture is present in the spark plug/ignition coil cavity of the cam cover, inspect the perimeter seal for damage. Repair tears in the perimeter seal with RTV sealant.
8. The J 26792 Spark Tester (ST 125) places a higher load on the secondary ignition than a normal spark plug.
13. Use the correct adaptor harness when connecting the J 43298 ignition module tester. Using an adaptor harness for a different engine application will result in incorrect tool operation.

The green Power LED should come on any time the ignition module tester is connected and the ignition switch is in the run position. This LED indicates that J 43298 Ignition Module Tester is receiving adequate power and ground to perform the test. The Test button is used as an LED check for the four red LEDs. To use this function, connect the tool, turn the ignition switch to run, then momentarily press the Test button. All four red LEDs should come on brightly. Then crank the vehicle. If the four red LEDs flash, this confirms proper operation of the primary ignition system (PCM, wiring, connections, and ICM). The Ignition Module Tester may get hot during actual testing. This is because it is attempting to simulate the load of the ignition coils primary windings.

If the LEDs flash, the module output drivers are operating. If one or more LEDs are inoperative, and no individual ignition control (IC) Circuit (DTC P0351-P0358), or IC Circuit Group (DTC P1359 and/or DTC P1360) are set, replace the module.