P1516 — Throttle Actuator Control (TAC) Module — Throttle Actuator Position Performance
CAUTIONIs it safe to drive? Drive gently and get it looked at soon — it can worsen or fail inspection.
What P1516 means
This is a manufacturer-specific code — its meaning depends on the vehicle’s make (see below).
What P1516 means on specific makes
Chevy / GMC / Cadillac / Buick CAUTION
GM electronic-throttle (drive-by-wire) fault: the TAC module sees the actual throttle blade position not matching the commanded position. Frequently drops the truck/car into reduced-power 'limp' mode. Common on GM trucks/SUVs.
- Dirty/failing throttle body ($0-30 clean, $150-350 replace)
- Throttle position sensor fault inside TB ($150-350)
- TAC module/wiring fault ($100-400)
- APP (pedal) sensor fault ($80-250)
Check first: Clean the throttle body first; if it persists, scan TAC data comparing commanded vs actual throttle position.
Source: GM code lists / engine-light-help