Throttle Actuator Control Module Performance
P2108 indicates that the Powertrain Control Module (PCM) has detected a performance issue with the Throttle Actuator Control (TAC) module. The TAC module controls the electronic throttle body, which regulates air intake based on accelerator pedal position. This code sets when the PCM detects that the actual throttle position does not match the commanded position, or there is a circuit malfunction within the TAC system. Common causes include a faulty throttle body, TAC module failure, wiring issues, or a defective accelerator pedal position sensor.
1. Most Common Causes
- Internal failure of the throttle actuator control (TAC) module
- Damaged throttle actuator motor
- Worn or failed internal gears in the throttle body
- Carbon buildup on the throttle plate causing mechanical resistance
- Fault in the power supply or ground circuit of the TAC module
- Corrosion or damage to the throttle body electrical connector
- Software or calibration fault in the ECM/PCM
- Electromagnetic interference in the ETC system wiring
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Reduced engine power or limp mode
- Poor acceleration or hesitation
- Engine stalling or rough idle
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm P2108 and check for other related codes.
Step 2: Visually inspect the throttle body and TAC module wiring for damage or loose connections.
Step 3: Test the throttle actuator control module and throttle body using a multimeter or scan tool to verify proper operation.
Step 4: Check the accelerator pedal position sensor signal and compare with throttle position readings.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
No, it is not safe. The vehicle may enter limp mode, reducing power and increasing the risk of accidents. Have it diagnosed and repaired promptly.
How much does it cost to fix?▼
Repair costs typically range from $150 to $400, depending on whether the throttle body or TAC module needs replacement and labor rates.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.