Throttle Body Performance (GM)
What does P1514 mean?
The P1514 code means the vehicle's onboard diagnostic system has detected: Throttle Body Performance (GM). This is a moderate severity code.
Common Symptoms
- Reduced engine power warning message
- Check Engine Light illuminated
- Throttle response is sluggish or delayed
- Engine may go into limp mode
- Idle speed may be unstable
Probable Causes (Ranked by Likelihood)
- Carbon buildup in the throttle body Very High
- Faulty throttle body actuator motor High
- Failed throttle position sensor inside the throttle body High
- Damaged wiring to the throttle body Moderate
- Faulty accelerator pedal position sensor Low
Step-by-Step Diagnostic Procedure
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Clean the throttle body bore and plate with throttle body cleaner. Carbon is the most common cause.
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Monitor the throttle position and accelerator pedal position on a scan tool for smooth operation.
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Check the throttle body connector for corrosion, loose pins, or water intrusion.
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Perform a throttle body relearn procedure after any cleaning or replacement.
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Test the accelerator pedal position sensor for smooth, linear output through its range.
Frequently Asked Questions
What causes the Reduced Engine Power message?
The ECM limits throttle opening when it detects the throttle body is not performing as expected. This is a safety measure to prevent unintended acceleration or loss of throttle control.
Can I clean the throttle body to fix this?
In many cases, yes. Carbon buildup is the number one cause of P1514 on GM trucks and SUVs. A thorough cleaning followed by a throttle body relearn often resolves the issue completely.
How do I perform a throttle body relearn?
On most GM vehicles, turn the key on but do not start the engine. Wait 30 seconds. Start the engine and let it idle for 3 minutes without touching the gas pedal. Some models require a scan tool for the relearn.