Throttle Actuator Control Module Throttle Actuator Position Performance

What it means

This is a Chevrolet (GM) manufacturer-specific code, and the same number can mean something different on other makes. The throttle actuator control (TAC) module found that the actual throttle plate position does not match where it should be. A sticking plate or weak throttle motor is the usual cause, and the system limits power until the fault clears.

Models covered: Chevrolet (GM) models with electronic throttle control, mainly around 1997–2006.

Related codes: P1515P2119P2101P1220P1221

Symptoms4

• Reduced power message and clearly weak acceleration.
• Unstable or slightly high idle.
• The fault may appear after a cold start or after washing the engine.
• Check engine light on, sometimes with P1515 stored.

Possible causes5

• A throttle plate sticking from carbon or dirt.
• A weak throttle motor or worn internal gears.
• Extra resistance in the throttle motor wiring or connector.
• Water in the connector after washing or rain.
• A fault in the TAC module itself (less common).

How to diagnose5

1. Read the codes and note whether the fault appears in a certain condition, such as cold weather or after washing.
2. With the engine off, check that the plate is clean and returns smoothly.
3. Watch commanded and actual throttle position on a scan tool while moving the pedal.
4. Check the throttle motor connector for water or corrosion and measure wiring resistance.
5. Rule out a weak battery or ground before blaming the module.

How to fix5

1. Carefully clean the throttle body.
2. Dry and clean the connector and repair damaged terminals.
3. Repair the wiring or weak ground.
4. Replace the throttle body if its motor is weak, then perform the relearn.
5. If the module is confirmed faulty, replace and program it per the manufacturer, then clear the codes and confirm they do not return.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

Cleaning and connector work keep the cost low, a throttle body puts it in the middle to high range, and a module that needs replacing and programming is the most expensive case.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions