Chart A2

The conditions diagnosed in ECM CHART A are caused by a single circuit failure that results in multiple diagnostic codes. If any of the following conditions are met, follow the appropriate correction procedure before using the procedures for the individual codes.

A-2
If a Code EO15 is stored as current along with a current Code EO21 or EO40, the cause is probably an open in the sensor ground (circuit # 1076A) for the TPS, Coolant, and Power Steering Pressure sensors. To verify this condition, probe the following harness terminals with a voltmeter to battery positive:
^ TPS Test Point Connector Pin A, Dk-Blu wire
^ Coolant Temperature Sensor Connector Pin B, Yel wire
^ Power Steering Pressure Sensor Connector Pin A, Gry wire

If the voltage is 0 at all three sensors, circuit # 1076A must be checked for an open between the ECM terminal E11 and the circuit # 1076A to 1076F/1076PC/1076PN splice. Refer to ECM Wiring Diagram "A". Electrical Diagrams

If the defect is not found in the wiring, either the ECM connector or ECM itself is faulty. Refer to PFI Chart C- 1 "ECM Replacement Check" before replacing the ECM. Chart C-1 PCM/ECM Replacement Check

If the proper 12 volt signal is observed on any of the sensors terminals, then the diagnostic procedure for each individual code must be followed. Diagnose Code EO15 first, then Code EO21, and then EO40.