P1523 GMC Code - Electronic Throttle Control Throttle Return

P1523 indicates an issue with the Electronic Throttle Control (ETC) system, specifically the Throttle Return Performance, meaning the throttle plate may not be returning to its default position as expected.

Symptoms may include an illuminated check engine light, reduced engine power mode activation, poor throttle response, rough idling, or stalling.

Possible causes include a malfunctioning throttle body, a faulty throttle position sensor, wiring issues, carbon buildup on the throttle plate, or a failing electronic throttle control module.

Driving with the P1523 code is not recommended, as it can lead to reduced engine performance or safety hazards due to unpredictable throttle behavior.

Start by inspecting the throttle body for carbon buildup or mechanical sticking. Use a scan tool to check throttle position sensor data and inspect related wiring and connectors for damage or loose connections.

The most common fix involves cleaning the throttle body to remove carbon buildup or replacing a faulty throttle position sensor if cleaning doesn’t resolve the issue.

Costs can vary, but cleaning the throttle body may cost $100–$200, while replacing a throttle position sensor or throttle body could range from $300 to $800, depending on parts and labor rates.

Yes, a software glitch in the ECM (Engine Control Module) may cause this code. A software update or reprogramming may be required in some cases.

You’ll need an OBDII scan tool to read and clear codes, a multimeter to test wiring and sensors, and possibly a throttle body cleaner to address buildup.

While rare, a failing ECM can potentially trigger this code if it is unable to correctly process throttle position signals or control the throttle actuator.