Chart 6 Multiple PCM Codes

PCM Sensor Circuit:

CIRCUIT DESCRIPTION
Some powertrain components share common feeds and returns. Certain failures of these circuits will cause multiple codes to set.

If all of the Powertrain Control Module (PCM) codes in one group under Multiple PCM Codes are set, perform the diagnosis listed under that heading. If all of the codes in a group are not set, diagnose the lowest code number first.

The electrical diagram in the accompanying image shows the relationship among the common feeds and/or returns.

MULTIPLE PCM CODES
1. PCM Codes PO22, PO32, P036 and P103 Set
CKT 474 is the 5 volt feed from the PCM to the Manifold Absolute Pressure (MAP) sensor and Throttle Position (TP) sensor, Exhaust Gas Recirculation (EGR) valve and Brake Booster Vacuum (BBV) sensor. An open or short to ground in CKT 474 between the PCM's pin "3E16" and splice S235 will cause Codes P022, P032, P036 and P103 to set.

Diagnosis
Check for an open or short to ground on CKT 474 between PCM pins "3E16" and splice S235

2. PCM Codes PO31 and PO38 Set
CKT 452 is the sensor return to the PCM from the Intake Air Temperature (IAT) sensor and MAP sensor. An open in CKT 452 between splice S237 and PCM will cause Codes P031 and P038 to set.

Diagnosis
Check for an open in CKT 452 between splice S237 and PCM.

3. PCM Codes PO31, PO38 and PO59 Set
CKT 452 is the sensor return to the PCM from the IAT sensor, MAP sensor and transaxle temperature sensor. An open CKT 452 between splice S237 and PCM's pin "2D1" will cause Codes P031, P038 and PO59 to set.

Diagnosis
Check for an open in CKT 452 between PCM pin "2D1" and splice S237.

4. PCM Codes P015, PO21, P036 and P102 Set
CKT 808 is the sensor return to the PCM from the EGR valve, Engine Coolant Temperature (ECT), BBV and TP sensor. An open CKT 808 between splice S236 and PCM will cause Codes P015, P021, P036 and P102 to set.

Diagnosis
Check for an open in CKT 808 between PCM pin "2C1" and splice S236.

5. PCM Codes PO29, P094 and P117 Set
CKT 741 is the battery feed from the engine compartment fuse block fuse "D1" to the transaxle shift "A/B" solenoids. An open in CKT 741 will cause Codes P029, P094, and P117 to set.

Diagnosis
Check for an open in CKT 741 between engine compartment fuse block fuse "D1" and splice S134 (inside transaxle).

6. PCM Codes P039 and P090 Set
CKT 741 is the battery feed from the engine compartment fuse block fuse "D1" to the Torque Converter Clutch (TCC) brake switch which feeds the torque converter clutch through CKT 420. An open in CKT 741 or CKT 420 or an open in the TCC contacts of the TCC brake switch will cause Codes P039 and P090 to set.

Diagnosis
Check for:
- An open in CKT 741 between engine fuse block fuse "D1" and pin "A" of the TCC brake switch

- An open in CKT 420 between connector C101 pin "P10" and pin "B" of the TCC brake switch

- Open TCC contacts of the TCC brake switch

7. PCM Codes P029, P039, P090, P094 and P117 Set
CKT 741 is the battery feed for the Transaxle Shift "A/B" solenoids, TCC brake switch and TCC. A short to ground on CKT 741, an open fuse "D1" or an open feed to fuse "D1" will cause Codes P029, P039, P090, P094 and P117 to set.

Diagnosis
Check for a short to ground on circuit CKT 741, an open engine compartment fuse block fuse "D1," and an open feed to fuse "D1."

AFTER REPAIRS
When all diagnosis and repairs are completed, clear codes and verify operation.