Ignition System: Service Precautions

DIS SYSTEM

FAILURE MODE EFFECTS MANAGEMENT (FMEM)

During some DIS faults, the FMEM portion of the DIS ignition module will maintain vehicle operation. The DIS module will automatically turn the ignition coils on and off using the profile ignition pickup (PIP) signal if it does not receive the Spout (Spark Out) input. This condition will result in fixed spark and fixed dwell timing. If the module does not receive the Cylinder Identification (CID) input, random coil synchronization will be attempted by the module. Several attempts may be required to start the engine when the DIS module is in this mode.


SYNCHRONIZER ASSEMBLY

Prior to starting the removal procedure, set cylinder No. 1 to 26 degrees (ATDC) of the compression stroke. Then note the position of the camshaft sensor electrical connector. This procedure requires that the connector be located in the same position.

A tool such as Syncro Positioner T89P-12200-A or equivalent must be obtained prior to installation if the replacement synchronizer does to contain a plastic locator cover tool. Failure to follow this procedure will result in improper alignment, which will cause the ignition and fuel system to be out of time with the engine, thus causing possible engine damage.

DO NOT reposition the connector by rotating the synchronizer base if the camshaft sensor electrical connector is not properly positioned. (Forward of the supercharger drive belt or contacting the A/C bracket) This will cause the fuel and ignition system to be out of time with the engine, causing possible engine damage. Instead, remove synchronizer and repeat installation procedure.

SPARK PLUG WIRES

Proper installation of spark plug wires is critical to vehicle operation. If one spark plug wire is not properly installed on spark plug or ignition coil, both spark plugs connected to ignition coil may not fire under load.