Chart A Multiple Codes Stored Hard

ECM Chart A:

DFI Sensor Circuit:

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

CHART A-1

If codes E022 and E032 are both stored hard, the cause is probably the loss of 5 volts on circuit #474 (5 volt reference to MAP and TPS).

To verify this condition, probe the following harness terminals with a voltmeter to ground:

1. MAP sensor harness connector Pin C
2. TPS connector Pin C.

If the voltage is 0 for the two sensors, circuit #474 MUST be investigated for an open or short to ground. If a defect is not found in the wiring, either the ECM connector or ECM itself is faulty. If the proper 5 -volt signal is observed on both sensor terminals, then the diagnostic procedures for each individual code must be followed. Diagnose E022 first, then code E032.

CHART A-2

If a code E015 is stored hard along with a hard code E021, or E026, the cause is probably an open in the sensor ground circuit #476 for the TPS and coolant sensors.

To verify this condition, probe the following harness terminals with a voltmeter to 12 volts:

1. Coolant Temp sensor Pin A, blk/pnk wire.
2. TPS connector Pin B, blk/pnk wire.

If the voltage is 0 at both sensors, circuit #476 be investigated for an open. If a defect is not found in the wiring, either the ECM connector or ECM itself is faulty. If 12 volts is observed at either of the two sensors, then the diagnostic procedures for each individual code must be followed. Diagnose code E015 then E021 then E026.

CHART A-3

If a code E031 is stored hard along with hard codes E038, and E059, this is probably caused by an open in the sensor ground circuit #476 for the MAP, MAT and TRANS TEMP sensors.

To verify this condition, probe the following harness terminals with a voltmeter to 12 volts:

1. MAT sensor Pin A.
2. MAP sensor harness Pin A.
3. TRANS TEMP sensor Pin A.

If the voltage is 0 for the sensors, circuit #476A must be investigated for an open. If a defect is not found in the wiring, either the ECM connector or ECM itself is faulty. If 12 volts is observed at the sensors, then the diagnostic procedures for each individual code must be followed. Diagnose code E031, then E038 and then E059.