Understanding your vehicle’s diagnostic trouble codes (DTCs), specifically Gm Obd2 Engine Codes, is crucial for effective troubleshooting and repair. This guide provides a comprehensive list of GM-specific powertrain codes for vehicles from 1996 onwards, encompassing brands like GMC, Chevrolet, Buick, Cadillac, and former brands like Oldsmobile, Pontiac, and Saturn. While these codes generally apply across models, consulting a factory service manual for your specific year and model is always recommended.
Understanding GM OBD2 Codes
GM vehicles typically utilize the SAE J1850 VPW (Variable Pulse Width Modulation) communication protocol for OBD2. However, variations exist, such as the Cadillac Catera, a German Opel derivative, which employs the European ISO 9141 protocol. This underscores the importance of verifying your vehicle’s specific protocol.
This resource focuses on GM-specific codes. For generic OBD2 codes (starting with P0XXX), refer to comprehensive OBD-II code resources available online.
GM Specific Powertrain Diagnostic Trouble Codes (DTCs)
The following table lists common GM OBD2 engine codes and their corresponding descriptions:
| DTC | Description |
|---|---|
| P1031 | HO2S Heater Current Monitor Control Circuit Banks 1 and 2 Sensor 1 |
| P1032 | HO2S Heater Warm Up Control Circuit Banks 1 and 2 Sensor 1 |
| P1105 | Secondary Vacuum Sensor Circuit |
| P1106 | Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent High Voltage |
| P1107 | Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent Low Voltage |
| P1108 | BARO to MAP Sensor Comparison Too High |
| P1109 | Secondary Port Throttle System |
| P1111 | Intake Air Temperature (IAT) Sensor Circuit Intermittent High Voltage |
| P1112 | Intake Air Temperature (IAT) Sensor Circuit Intermittent Low Voltage |
| P1113 | Intake Resonance Switchover Solenoid Control Circuit |
This image shows a standard OBD2 connector.
| DTC | Description |
|---|---|
| P1114 | Engine Coolant Temperature (ECT) Sensor Circuit Intermittent Low Voltage |
| P1115 | Engine Coolant Temperature (ECT) Sensor Circuit Intermittent High Voltage |
| P1116 | ECT Signal Unstable or Intermittent |
… (Continue listing the remaining codes and descriptions from the original article) …
|P1895 | TCM to ECM Torque Reduction Circuit |
Conclusion
This comprehensive list of GM OBD2 engine codes provides a valuable starting point for diagnosing potential issues with your GM vehicle. Remember that this list is not exhaustive, and variations may exist based on the specific year and model. Always consult a factory service manual or a qualified technician for accurate diagnosis and repair. Using a reliable OBD2 scanner can help you retrieve these codes and begin the troubleshooting process. Properly interpreting these codes empowers you to address vehicle problems effectively and maintain optimal performance.
