Powertrain Control Module Diagnosis General Information
To read and clear diagnostic trouble codes, use a scan tool.
Use a scan tool to clear diagnostic trouble codes from the PCM memory. Diagnostic trouble codes can also be cleared by turning OFF the ignition and disconnecting the battery power from the PCM for 30 seconds, but this method will also cause all diagnostic information in the PCM memory to be cleared and all the diagnostic tests will have to be re-run.
The Vehicle Identification Number (VIN) is programmed into the PCM. Do not exchange a PCM from another vehicle for testing or replacement. When replacing the PCM, the VIN must also be programmed into the new PCM.
Because the PCM can have a failure which may affect only one circuit, follow the diagnostic procedures in this section to determine which circuit has a problem and where it is.
If a diagnostic chart indicates that the PCM connections or PCM is the cause of a problem and the PCM is replaced, but does not correct the problem, one of the following may be the reason:
| • | There is a problem with the PCM terminal connections. The diagnostic chart will say PCM connections or PCM. The terminals may have to be removed from the connector in order to check them properly. |
| • | EEPROM program is not correct for the application. Incorrect components may cause a malfunction and may or may not set a DTC. |
| • | The problem is intermittent. This means that the problem is not present at the time the system is being checked. In this case, refer to the Symptoms portion of the manual and make a careful physical inspection of all components and wiring associated with the affected system. |
| • | There is a shorted solenoid, relay coil, or harness. Solenoids and relays are turned ON and OFF by the PCM using internal electronic switches called drivers. Each driver is part of a group of seven called Output Driver Modules. A shorted solenoid, relay coil, or harness will not damage the PCM but will cause the solenoid or relay to be inoperative. The J 34636 tester, or equivalent, provides a fast, accurate means of checking for a shorted coil or a short to battery voltage. |
Powertrain Control Module Diagnosis PCM DTCs
DTC Description | Type | Illuminate MIL |
|---|---|---|
DTC P0101 Mass Air Flow System Performance | A | Yes |
DTC P0102 MAF Sensor Circuit Low Frequency | A | Yes |
DTC P0103 MAF Sensor Circuit High Frequency | A | Yes |
DTC P0107 MAP Sensor Circuit Low Voltage | B | Yes |
DTC P0108 MAP Sensor Circuit High Voltage | B | Yes |
DTC P0112 IAT Sensor Circuit Low Voltage | B | Yes |
DTC P0113 IAT Sensor Circuit High Voltage | B | Yes |
DTC P0117 ECT Sensor Circuit Low Voltage | B | Yes |
DTC P0118 ECT Sensor Circuit High Voltage | B | Yes |
DTC P0121 TP Sensor Performance | A | Yes |
DTC P0122 TP Sensor Circuit Low Voltage | A | Yes |
DTC P0123 TP Sensor Circuit High Voltage | A | Yes |
DTC P0125 ECT Excessive Time to Closed Loop | B | Yes |
DTC P0131 HO2S Circuit Low Voltage Sensor1 | B | Yes |
DTC P0132 HO2S Circuit High Voltage Sensor1 | B | Yes |
DTC P0133 HO2S Circuit Slow Response Sensor1 | B | Yes |
DTC P0134 HO2S CKT Insufficient Activity Sensor1 | B | Yes |
DTC P0135 HO2S Heater Circuit Sensor1 | B | Yes |
DTC P0137 HO2S Circuit Low Voltage Sensor2 | B | Yes |
DTC P0138 HO2S Circuit High Voltage Sensor2 | B | Yes |
DTC P0140 HO2S CKT Insufficient Activity Sensor2 | B | Yes |
DTC P0141 HO2S Heater Circuit Sensor2 | B | Yes |
DTC P0171 Fuel Trim System Lean | B | Yes |
DTC P0172 Fuel Trim System Rich | B | Yes |
DTC P0300 Engine Misfire Detected | B | Yes |
DTC P0325 Knock Sensor Module Circuit | D | No |
DTC P0326 Knock Sensor Noise Channel High Voltage | D | No |
DTC P0327 Knock Sensor Noise Channel Low Voltage | D | No |
DTC P0336 24X Reference Signal Circuit | B | Yes |
DTC P0341 CMP Sensor Circuit Performance | B | Yes |
DTC P0401 EGR System Flow Insufficient | A | Yes |
DTC P0420 TWC System Low Efficiency | A | Yes |
DTC P0440 EVAP System Control | A | Yes |
DTC P0441 EVAP System No Flow During Purge | B | Yes |
DTC P0442 EVAP Control System Small Leak Detected | A | Yes |
DTC P0446 EVAP Canister Vent Blocked | A | Yes |
P0502 Vehicle Speed Sensor Circuit - Low Input (Refer To 4T60-E Automatic Transaxle Diagnosis) | A | Yes |
P0503 Vehicle Speed Sensor Circuit - Intermittent Input (Refer To 4T60-E Automatic Transaxle Diagnosis) | A | Yes |
DTC P0506 Idle Control System Low RPM | B | Yes |
DTC P0507 Idle Control System High RPM | B | Yes |
DTC P0530 A/C Refrigerant Pressure Sensor Circuit or DTC P0530 A/C Refrigerant Pressure Sensor Circuit | D | No |
DTC P0560 System Voltage | D | No |
DTC P0601 PCM Memory | A | Yes |
DTC P0602 PCM Not Programmed | D | No |
DTC P0705 Trans Range Switch Circuit | D | No |
DTC P0706 Transaxle Range Switch Performance | D | No |
P0712 Transaxle Fluid Temperature (TFT) Sensor Circuit - Low Signal Voltage (Refer To 4T60-E Automatic Transaxle Diagnosis) | A | Yes |
P0713 Transaxle Fluid Temperature (TFT) Sensor Circuit - High Signal Voltage (Refer To 4T60-E Automatic Transaxle Diagnosis) | A | Yes |
P0719 Brake Switch Circuit Low (Refer To 4T60-E Automatic Transaxle Diagnosis) | D | No |
P0724 Brake Switch Circuit High (Refer To 4T60-E Automatic Transaxle Diagnosis) | D | No |
P0742 Torque Converter Clutch Circuit Stuck On (Refer To 4T60-E Automatic Transaxle Diagnosis) | A | Yes |
P0751 Shift Solenoid 1 - Performance/Stuck Off (Refer To 4T60-E Automatic Transaxle Diagnosis) | B | Yes |
P0753 Shift Solenoid 1 - Electrical (Refer To 4T60-E Automatic Transaxle Diagnosis) | A | Yes |
P0756 Shift Solenoid 2 - Performance/Stuck Off (Refer To 4T60-E Automatic Transaxle Diagnosis) | B | Yes |
P0758 Shift Solenoid 2 - Electrical (Refer To 4T60-E Automatic Transaxle Diagnosis) | A | Yes |
DTC P1106 MAP Sensor CKT Intermittent High Voltage | D | No |
DTC P1107 MAP Sensor CKT Intermittent Low Voltage | D | No |
DTC P1111 IAT Sensor CKT Intermittent High Voltage | D | No |
DTC P1112 IAT Sensor CKT Intermittent Low Voltage | D | No |
DTC P1114 ECT Sensor CKT Intermittent Low Voltage | D | No |
DTC P1115 ECT Sensor CKT Intermittent High Voltage | D | No |
DTC P1121 TP Sensor CKT Intermittent High Voltage | D | No |
DTC P1122 TP Sensor CKT Intermittent Low Voltage | D | No |
DTC P1133 HO2S Insufficient Switching Sensor1 | B | Yes |
DTC P1134 HO2S Transition Time Ratio Sensor1 | B | Yes |
DTC P1200 Injector Control Circuit | B | Yes |
DTC P1336 CKP System Variation Not Learned | A | Yes |
DTC P1350 Bypass Line Monitor | B | Yes |
DTC P1361 IC Circuit Not Toggling | B | Yes |
DTC P1374 3X Reference Circuit | B | Yes |
DTC P1380 EBCM DTC Rough Road Data Unusable | D | No |
DTC P1406 EGR Valve Pintle Position Circuit | B | Yes |
DTC P1441 EVAP System Flow During Non-Purge (Oldsmobile Only) or DTC P1441 EVAP System Flow During Non-Purge Chevrolet Only | B | Yes |
DTC P1554 Cruise Control Status Circuit | D | No |
DTC P1626 Theft Deterrent System Fuel Enable CKT | D | No |
DTC P1629 Theft Deterrent Crank Signal Malfunction | D | No |
DTC P1635 5 Volt Reference (A) Circuit or DTC P1635 5 Volt Reference (A) Circuit | B | Yes |
DTC P1639 5 Volt Reference (B) Circuit or DTC P1639 5 Volt Reference (B) Circuit | D | No |
DTC P1641 MIL Control Circuit | D | No |
DTC P1651 Fan 1 Relay Control Circuit or DTC P1651 Fan 1 Relay Control Circuit | B | Yes |
DTC P1652 Fan 2 Relay Control Circuit or DTC P1652 Fan 2 Relay Control Circuit | B | Yes |
DTC P1654 A/C Relay Control Circuit | D | No |
DTC P1655 EVAP Purge Solenoid Control Circuit or DTC P1655 EVAP Purge Solenoid Control Circuit | B | Yes |
DTC P1662 Cruise Control Inhibit Control Circuit | D | No |
DTC P1663 Generator Lamp Control Circuit | D | No |
DTC P1671 Oil Change Lamp Control Circuit | D | No |
DTC P1672 Low Engine Oil Level Lamp Control CKT | D | No |
P1812 Transaxle Over Temperature Condition (Refer To 4T60-E Transaxle Diagnosis) | A | Yes |
P1860 Torque Converter Clutch PWM Solenoid Circuit (Refer To 4T60-E Transaxle Diagnosis) | A | Yes |
P1864 Torque Converter Clutch Enable Solenoid Circuit (Refer To 4T60-E Transaxle Diagnosis) | A | Yes |
P1870 Transaxle Component Slipping (Refer To 4T60-E Transaxle Diagnosis) | A | Yes |
