Pcm Code EO23, Est Circuit Problem (2 Of 2)

NOTE: Step numbers refere to test steps of flow chart.

1. 5)  This checks if HEI module can recognize a voltage on by-pass circuit and stop grounding EST (PCM-controlled timing).
2. 6)  This checks by-pass signal to module. If by-pass signal is being sent by PCM to HEI, and if module is interpreting by-pass voltage correctly, then module will switch off ground to EST.
3. 7)  If chart leads to EST CIRCUIT is okay, then a fault may exist in the 6-way connector. Check connector and terminals damage. If connector is okay, plug in connector and retest Code EO23.

Fig 1: PCM Code EO23, Schematic, EST Circuit Problem

Fig 2: Flow Chart 2 Of 2, PCM Code EO23, EST Circuit Problem