P2107: Throttle Actuator Control Module Processor

What it means

The internal processor or watchdog of the throttle actuator control module reports an internal fault. Communication between the TAC monitor core and the main ECU core has failed plausibility — typical for a defective ECU.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The throttle actuator control module processor supervises electronic throttle operation and checks internal control logic. P2107 sets when the module reports an internal processor or watchdog fault; it points to a control-module concern but does not by itself confirm whether hardware, software, or a supply problem is responsible.

Common causes

Most likely first.

1. ECU internal processor fault
2. ECU software flash corrupted
3. Module software outdated, reflash may resolve

Symptoms

• Check engine light on
• Reduced throttle response, possible limp mode
• Hesitation or surging
• Idle too high or too low

How to diagnose it

1. Save freeze-frame data and scan all modules for communication, voltage, and throttle-control codes that could explain or accompany the processor fault.
2. Check battery condition and inspect the control module's power, ground, and connectors for poor contact, corrosion, or damage.
3. Review available module identification and software information, and check whether the manufacturer documents a relevant update for this vehicle.
4. Verify module power, ground, and communication circuits using the wiring diagram and manufacturer's procedure before condemning the processor.
5. If external circuits are sound, follow the manufacturer's diagnostic guidance to assess module software or internal failure.

Common fixes

• Clean and secure corroded or loose control-module connections.
• Repair faulty module power, ground, or communication wiring.
• Apply a manufacturer-approved software update if it addresses the fault.
• Replace or reprogram the module if diagnosis confirms an internal processor failure.

Can I keep driving?

Throttle response may be limited or unreliable, so avoid high-speed driving and situations that require quick acceleration. If the vehicle enters limp mode or stalls, stop somewhere safe and arrange service.