Common GM check engine codes include: P1510, which indicates a problem with the backup air supply; P1525, which warns that throttle body service is required; P1545, which shows a problem with the air conditioner clutch relay control circuit; P1554, which indicates an issue with the speed control status circuit; and P1620, which suggests that the engine coolant level is low. Check engine codes may be vehicle specific. For example, the P1620 applies only to Saturn vehicles.Continue Reading
Check engine codes allow for the diagnosis of vehicle problems. On the dashboard, the words "check engine" appear or an engine symbol lights up when a problem triggers a code. The dashboard does not provide any additional information. In order to discover the precise code, the owner or mechanic needs a code reader.
The code reader attaches to an automobile's instrument panel. The check engine code provides the owner or mechanic with a general idea of what system or part may need a repair. The codes do not provide specific information. Instead, the vehicle needs additional diagnostic tests before a repair can begin. Vehicle service manuals contain information that can assist in determining the needed repair.
Check engine codes are part of a vehicle's on-board diagnostic system. All cars sold in the United States must contain an on-board diagnostic system.Learn more about Car Makes & Models