GM Service Manual Online
For 1990-2009 cars only

Circuit Description


Object Number: 899497  Size: MF

The PCM controls dwell and spark timing during all engine running conditions. The electronic ignition (EI) module charges the coil pack when the PCM supplies 5 volts to the 2/3 coil. The coil will then discharge or fire through its secondary coil towers whenever the voltage supply has been turned OFF by the PCM.

Conditions for Setting the DTC

During cranking the PCM pulses, the ignition control (IC) circuit high and low. The PCM monitors the diagnostic feedback circuit to diagnose circuit faults.

Important: IC circuit 2 and 3 is checked continuously whenever crankshaft position pulses are received by the PCM during cranking mode only.

DTC P0352 will set if there is an open, short to voltage, or short to ground in IC 2 and 3, circuit 406.

OR

DTC P0352 and P1352 will set if there is a short to voltage in IC 2 and 3, circuit 406, when the engine is in cranking mode.

Diagnostic Aids

The IC circuit consists of an ignition module, circuit 406, and the PCM.

Important: If there is an open in the IC 2 and 3 circuit, a misfire on those cylinders will occur.

    • A malfunctioning 2-3 coil, secondary wire, or 2-3 spark plug will not cause a DTC P0352 and/or P1352 to set.
    • A blown EIS fuse will cause a no start condition, but an IC 2 and 3 DTC should not set.
    • A blown EIS fuse will cause a no start condition, but an IC 2 and 3 DTC should not set. This fault will set a DTC P0340 if the engine was cranked long enough.
    • A fault on the IC circuit while running will result in a misfire DTC P0300.

Object Number: 900131  Size: FP