P1516 on GMC

Throttle actuator control (TAC) module fault (GM)

Severity: Inspect soon

GM bulletins pair P1516 with reduced engine power, so the truck or car may lose power while driving; get it checked soon.

It gets more serious if:

Stop: Stop driving if engine power drops sharply in traffic or the vehicle will not keep speed safely.

Source: how we rate severity

This page covers only what differs on GMC. For what P1516 means, the ranked causes and the test order, see the P1516 guide.

What's different on GMC

GMC

2003 · Sierra
Supported by vehicle data
GM 3040 pairs P1516 with a Service Engine Soon light or reduced engine power on the 2003 Sierra. Whether the bulletin is still current is not verified.

3040Status unverified
Service Engine Soon and/or reduced engine power, P0120, P0220, P1516, P1518
2003avalanche, silverado, suburban · NHTSA 10009377
Condition is normally very intermittent.
We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Sources and review

GM 3040: Service Engine Soon and/or reduced engine power, DTCs P0120, P0220, P1516 and/or P1518 — General Motors via NHTSA
GM 3089: Service Engine Soon and reduced engine power with DTC P1516 — General Motors via NHTSA

Last reviewed: October 15, 2026
Written by: Saurabh K.
Editorial review: Pending
Technician review: Technician review pending

This page explains what a code usually means; it is not a substitute for a professional inspection. How we source and review · Report an error