Understanding your vehicle’s diagnostic trouble codes (DTCs) is crucial for effective troubleshooting and repair. This guide focuses on Gm Obd2 Diagnostic Trouble Codes, providing a comprehensive list of codes specific to General Motors vehicles. These codes apply to most OBD-II compliant GM models manufactured from 1996 onwards, encompassing brands like GMC, Chevrolet, Buick, Cadillac, and discontinued brands such as Oldsmobile, Pontiac, and Saturn.
While this list covers a wide range of potential issues, consulting a factory service manual for your specific year and model is always recommended. Minor variations in DTC definitions can exist. Remember, this guide focuses on GM-specific powertrain codes. For generic OBD-II codes (starting with P0XXX), refer to this comprehensive resource.
Decoding GM OBD2 Trouble Codes
The following table lists common GM OBD2 diagnostic trouble codes, along with their corresponding descriptions. This information can help you pinpoint the potential source of a problem, enabling you to address it efficiently.
| 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 |
| 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 |
| P1117 | Engine Coolant Temp. Signal Out-Of-Range Low |
| P1118 | Engine Coolant Temp. Signal Out-Of-Range High |
| P1119 | ECT Signal Out-Of-Range With TFT Sensor |
| P1200 | Injector Control Circuit |
| P1250 | Early Fuel Evaporation Heater Circuit |
| P1258 | Engine Coolant Overtemperature – Protection Mode Active |
| P1345 | Crankshaft Position (CKP)-Camshaft Position (CMP) Correlation |
| P1404 | Exhaust Gas Recirculation (EGR) Closed Position Performance |
| P1500 | Starter Signal Circuit |
(This table includes a partial list of codes. Consult a service manual for a complete listing for your specific vehicle.)
Utilizing GM OBD2 Codes for Diagnostics
These GM OBD2 diagnostic trouble codes provide a starting point for diagnosing vehicle problems. Using an OBD2 scanner, you can retrieve these codes and begin investigating the underlying issue.
Remember:
- Accurate Diagnosis: While DTCs offer valuable clues, they don’t always pinpoint the exact problem. Further diagnostic steps, such as visual inspections, component testing, and using a factory service manual, are often necessary.
- Severity of Codes: Not all codes indicate equally serious problems. Some might signal minor issues, while others could point to significant malfunctions requiring immediate attention.
- Code Clearing: After addressing a problem, it’s essential to clear the codes using an OBD2 scanner. This confirms the repair and prevents old codes from causing confusion.
Conclusion
Understanding and utilizing GM OBD2 diagnostic trouble codes empowers you to take a proactive approach to vehicle maintenance and repair. By familiarizing yourself with these codes and employing proper diagnostic techniques, you can effectively address vehicle issues and keep your GM vehicle running smoothly. Always consult a qualified technician for complex problems or if you’re unsure about performing repairs yourself.
