E012

Code E012:

HEI Circuit Detail:

DESCRIPTION:

Possible causes of "no distributor reference" are:

1. Open or shorts on CKT 430 from distributor module to PCM/ECM.
2. HEI module unable to process pick-up coil signals to produce distributor reference pulses.
3. The grounding screw is located on the metal tab that is attached to the plastic fitting on the five wire harness.

TEST CONDITIONS:

Code E012 is tested any time cam sensor signals are being received.

FAILURE CONDITIONS:

If the PCM/ECM does not see distributor reference pulses for 4.0 seconds with cam references being received, code E012 will be set.

ACTION TAKEN:

1. The PCM/ECM turns on "SERVICE ENGINE SOON" telltale.

NOTES ON FAULT TREE:

1. Checking for proper voltage output of the HEI system. If the voltmeter shows .5 to 2.8 volts, then HEI is producing reference pulses.

2. Checking for proper ground connection between the PCM/ECM and the HEI module.

3. Checking for proper voltage through CKT 43O from HEI to the PCM/ECM. If PCM/ECM terminal D8 has .5 to 2.8 volts, then the PCM/ECM is receiving reference pulses.

4. Checking for HEI module operation. If the HEI system will produce a spark, then the fault is not at the pick-up coil or module.

NOTE ON INTERMITTENTS:

If code E012 is stored as a history code, start the engine and allow to idle while manipulating CKT 430 and 453. An intermittent open will cause the engine to stumble or quit when the PCM/ECM loses distributor reference signals. If the wiring and PCM/ECM connectors are OK, check the HEI pick up coil leads for an intermittent open circuit.