What it means
The throttle actuator control module did not perform as expected. The code does not identify a particular failed self-test or establish that the ECU is aging.
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 manages throttle operation and runs performance checks on its control functions. P2108 sets when the module fails a performance check; the code does not specify which check failed, so related codes and circuit checks are needed to narrow the cause.
Common causes
Most likely first.
- ECU internal performance fault
- ECU connector pins corroded
- Module software outdated, reflash may resolve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
- Record freeze-frame data and scan all modules for companion throttle, voltage, or communication codes that may identify the failed performance condition.
- Inspect the control-module connectors and wiring for corrosion, loose pins, damage, or poor power and ground connections.
- Check live throttle and pedal data for implausible values or tracking problems that could make the module appear to perform incorrectly.
- Test module power, ground, and communication circuits against the wiring diagram and manufacturer's procedure.
- Check manufacturer software information and updates; if circuits and inputs are sound, follow the specified module performance tests.
Common fixes
- Clean and secure corroded or loose module connector terminals.
- Repair damaged power, ground, or communication wiring to the control module.
- Install a manufacturer-approved software update if applicable to the diagnosed fault.
- Repair or replace the module if the specified tests confirm an internal performance failure.
Can I keep driving?
The fault can lead to reduced power or unpredictable throttle response; avoid overtaking and high-speed travel until diagnosed. If power limitation prevents safe movement with traffic, pull over and arrange recovery.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.