What does it mean?
P1516 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance .
Symptoms
- Check engine light on together with reduced power or limp mode
- Engine speed limited so the car will not accelerate normally
- Throttle response delayed, jerky or surging at steady speed
- Erratic or hunting idle
- Cruise control disabled
- Engine may return to normal after a restart and then fail again
Likely causes
- Carbon deposits around the throttle plate and bore preventing it from reaching the commanded angle
- Worn or failing throttle actuator motor or its gear train
- Throttle position sensors inside the throttle body reading out of correlation
- Damaged connector, corroded pins or chafed wiring at the throttle body
- Low system voltage or poor engine and module grounds
- Broken or weakened throttle return spring
- Internal fault in the throttle actuator control module or the engine control module
How to fix it
- Read all throttle related codes and freeze frame, then watch commanded against actual throttle position in live data while sweeping the pedal
- Inspect the throttle bore and plate for carbon and clean it with the recommended method
- Check both throttle position signals for smooth, correlated movement without dropouts
- Check battery voltage, charging output and the engine and module ground points
- Inspect the throttle body connector and harness for corrosion, bent pins and chafing
- Carry out the throttle relearn procedure after cleaning or any connector work
- Replace the throttle body if the motor or its sensors are faulty, and treat the control module as the final step