A failing throttle actuator control module or electronic throttle body assembly; Worn or dirty internal components within the throttle body, such as the motor brushes or position sensor tracks; Corroded, loose, or damaged wiring and connectors at the throttle body or module; A weak or failing battery or charging system causing low voltage to the module; A software or calibration issue in the engine control module requiring a reflash; An intermittent ground fault on the throttle actuator control circuit; Mechanical binding or carbon buildup on the throttle plate preventing smooth movement

DTC codes / P21xx · Fuel and air metering / P2108

P2108Throttle Actuator Control Module Performance

Q: What does code P2108 mean?

Throttle Actuator Control Module Performance. P2108 means the engine computer has detected a performance fault within the throttle actuator control module, which is the electronic assembly that moves the throttle plate in response to accelerator pedal input. The computer compares commanded throttle position against actual throttle position and flags the module when the correlation falls outside the expected range or when the module fails its internal self-test.

P2108 means the engine computer has detected a performance fault within the throttle actuator control module, which is the electronic assembly that moves the throttle plate in response to accelerator pedal input. The computer compares commanded throttle position against actual throttle position and flags the module when the correlation falls outside the expected range or when the module fails its internal self-test.

SystemPowertrain

Code typeGeneric (all makes)

SeverityHigh

Fix difficultyProfessional

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode, limiting vehicle speed
A throttle pedal that feels unresponsive or delayed
Rough or erratic idle quality
The engine may stall or hesitate when accelerating from a stop
A warning message on the dashboard such as 'Service Electronic Throttle Control'

Common causes, most likely first

A failing throttle actuator control module or electronic throttle body assembly
Worn or dirty internal components within the throttle body, such as the motor brushes or position sensor tracks
Corroded, loose, or damaged wiring and connectors at the throttle body or module
A weak or failing battery or charging system causing low voltage to the module
A software or calibration issue in the engine control module requiring a reflash
An intermittent ground fault on the throttle actuator control circuit
Mechanical binding or carbon buildup on the throttle plate preventing smooth movement

How to diagnose and fix it

Scan all modules for stored and pending codes, then record freeze-frame data to understand the conditions when P2108 set
Inspect the throttle body, connector pins, and wiring harness for corrosion, chafing, or loose terminals
Test battery voltage and charging system output to rule out low-voltage faults before condemning the module
Perform a throttle body cleaning and relearn procedure if carbon buildup or binding is found
Check for technical service bulletins or software updates for the engine control module and throttle actuator control module
Perform a bidirectional scan-tool test of the throttle actuator to command the plate open and closed while watching position sensor feedback
Replace the electronic throttle body or throttle actuator control module only after electrical and mechanical checks pass, then perform the required adaptation or relearn

What the throttle actuator code really means

A dirty throttle body is a common cause of P2108 that many people miss because the code points at the module rather than at mechanical binding of the plate.
Low battery voltage or a failing alternator can set this code intermittently, so always verify charging system health before replacing the throttle body.
The throttle actuator control module is often integrated into the electronic throttle body on many vehicles, so the whole assembly may need replacement rather than a separate module.
P2108 does not always mean the module is dead; a poor ground connection or corroded connector pin can produce the same performance fault.
After replacement, a throttle body relearn or adaptation procedure is mandatory on most vehicles, and skipping it can cause a repeat code or poor idle.

Can I keep driving with P2108?

If the vehicle is in limp mode or the throttle response is erratic, avoid driving until the fault is diagnosed because sudden loss of power can be dangerous. If the only symptom is the warning light and the car drives normally, you can drive cautiously to a repair shop, but do not tow or carry heavy loads.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.