Ignition Control Not Operating Properly LT1

An open IC circuit will set a DTC 41. Refer to DTC 41. A grounded IC circuit will set a DTC 42. Refer to DTC 42. An open or grounded IC circuit will result in a no crank condition. Refer to No Crank .

An open or ground in the low resolution signal circuit will set a DTC 16 and the engine will not start. Refer to DTC 16. If the high resolution signal circuit becomes open or grounded, a DTC 36 would set. Refer to DTC 36. This will cause reduced performance and poor fuel economy.

The PCM uses information generated by the following sources in order to calculate spark advance:

1. The MAP sensor
2. The ECT sensor
3. The engine RPM

The PCM determines that more spark advance is required when the following conditions exist:

1. A cold engine
2. A minimum load, based on engine RPM and low air flow

The PCM determines that less spark advance is required when the following conditions exist:

1. A hot engine
2. A heavy load, based on engine RPM and high air flow