Pcm Code E23, Est CKT Problem: Action
PCM turns on SERVICE ENGINE SOON light. PCM-controlled spark is disabled for ignition cycle.
NOTE:
Test numbers refer to numbers on diagnostic chart.
- Use 4 jumper wires in diagnostic procedure. Jumper wires should be about 12" long with Weatherpack Connector (12014836 and 12014837) on either end. With distributor connector disconnected, use jumpers to reconnect terminals per instructions provided on PCM Code E23 chart.
- With only distributor reference and distributor reference ground jumpered, engine will run at back-up spark. Check for proper ground connection between PCM and engine and between PCM and HEI.
- Checks PCM ability to provide an EST output on circuit No. 423.
- Checks HEI module ability to ground EST signal with open by-pass circuit.NOTE: Test numbers refer to numbers on diagnostic chart.
- Checks HEI module ability to recognize a voltage on by-pass circuit and to stop grounding EST (PCM controlling timing).
- Checks for by-pass signal to module. If by-pass is being sent by PCM to HEI and if module is interpreting by-pass voltage correctly, module will switch off ground to EST.
- If chart leads to EST circuit and circuit is okay, a fault may exist in 6-way weatherpack. Check for proper connector mating and for pins backing out of weatherpack. If connector is okay, reconnect 6-way connector, clear codes and retest.