Trouble Code Identification
NOTE:
Trouble codes retrieved from PCM/TCM may be related to either engine or transmission. Transmission-related codes are covered in this article. For engine-related codes, see appropriate G - TESTS W/ CODES article. See TROUBLE CODE IDENTIFICATION table to determine if code is transmission or engine related.
- The system codes indicate failure of a specific sensor and/or circuit. Sensor/circuit diagnosis may indicate replacement of the control unit. Code 51 indicates PROM/MEM-CAL is installed improperly or has failed.
- Code 52 indicates PCM/TCM has failed and must be replaced. If the condition is still not corrected after replacing PCM/TCM, the cause may be as follows.
- An incorrect PCM/TCM or PROM/MEM-CAL application may cause a malfunction, which may or may not set a code.
- The PCM/TCM connector may be the problem. Connector terminals may have to be removed from the connector to be properly checked.
- PROM/MEM-CAL failure. Although the PROM/MEM-CAL rarely fails, it could be the cause of the problem.
- Replacement PCM/TCM may be faulty.
- Intermittent problem. Make a careful physical inspection of affected sensor/circuit.
- A shorted solenoid, coil relay, or harness may be the cause of PCM/TCM failure. Use Short Circuit Tester (J-34636) to check for short circuits.
TROUBLE CODE IDENTIFICATION
| Code | Probable Cause | ||
|---|---|---|---|
| 12 (1) | No Engine Speed Sensor Reference Pulse To PCM/TCM | ||
| 13 (1) | Open Oxygen Sensor Circuit (Gasoline) | ||
| 14 (1) | CTS Voltage Low (Sensor Or Signal Line Grounded) | ||
| 15 (1) | CTS Voltage High (Sensor, Connections, Or Wires Open) | ||
| 21 (1) | TPS Voltage High (Open Circuit Or Misadjusted TPS) | ||
| 22 (1) | TPS Voltage Low (Circuit Grounded) | ||
| 23 (1) | TPS Not Calibrated (Diesel - .25-1.3 Volts At Curb Idle) | ||
| 23 (1) | Intake Air Temperature Sensor Voltage High (Gasoline) | ||
| 24 (1) | Vehicle Speed Sensor Circuit Open Or Grounded | ||
| 25 (1) | Intake Air Temperature Sensor Voltage Low (Gasoline) | ||
| 28 | Pressure Switch Manifold Range Circuit Open Or Shorted | ||
| 31 (1) | MAP Voltage Low (Diesel) | ||
| 31 (1) | Turbocharger Wastegate Overboost (Gasoline) | ||
| 32 (1) | EGR Error (Improper Vacuum Signal) | ||
| 33 (1) | MAP Voltage High | ||
| 34 (1) | MAP Voltage Low (Gasoline) | ||
| 35 (1) | IAC System Fault (Gasoline) | ||
| 39 | TCC Stuck Off (Faulty TCC Solenoid) | ||
| 42 (1) | EST Circuit Fault (Gasoline) | ||
| 43 (1) | ESC Fault (Gasoline) | ||
| 44 (1) | Lean Exhaust Indicated (Gasoline) | ||
| 45 (1) | Rich Exhaust Indicated (Gasoline) | ||
| 51 (1) | Improperly Installed/Faulty PROM/MEM-CAL | ||
| 52 (1) | PCM/TCM Fault | ||
| 53 | System Voltage High (Gasoline - Charging Problem) | ||
| 53 | Voltage Reference Overload (Diesel) | ||
| 54 (1) | Fuel Pump Circuit Voltage Low (Gasoline) | ||
| 55 (1) | Faulty ECM (Gasoline) | ||
| 58 | TTS High Temperature (Sensor Or Signal Line Grounded) | ||
| 59 | TTS Low Temperature (Sensor, Connections, Or Wires Open) | ||
| 68 | Overdrive Ratio Error (Engine RPM Greater Than Input Speed) | ||
| 73 | Force Motor Commanded Amperage Differs From Return | ||
| 75 | System Voltage Low (Charging System Problem) | ||
| 81 | QDM Solenoid "B" Monitored Voltage Differs From Commanded | ||
| 82 | QDM Solenoid "A" Monitored Voltage Differs From Commanded | ||
| 83 | QDM TCC Monitored Voltage Differs From Commanded | ||
| 85 | Undefined Gear Ratio (Input Or Output Sensor Failure) | ||
| 86 | Shift Solenoid "B" Stuck On (Commanded Gear Not Engaged) | ||
| 87 | Shift Solenoid "B" Stuck Off (Commanded Gear Not Engaged) | ||
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