U0408Invalid Data Received From Throttle Actuator Control Module
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- U0408 points to messages from the throttle actuator control module that the receiver, usually the ECM/PCM, judges invalid: implausible content, a failed checksum or counter, or a value outside its range. Most vehicles integrate throttle control in the engine controller, so a separate TAC module and therefore this code are uncommon; no manufacturer documents U0408 publicly. Ford's 2012 OBD summary illustrates the U04xx logic with U0401, which the TCM stores when ECM torque or pedal data are faulted. Because the throttle meters intake air, CARB's comprehensive component rules apply, and a MIL together with reduced power or a limp mode is likely. U0107 means lost contact, U0308 a software mismatch with the same module.
- What you may notice
- Check engine light on
- Limp mode with reduced throttle response
- Unstable idle or stalling
- Likely causes
- PossibleDamaged bus wire or poor connector contact at the throttle module
- PossibleThrottle actuator control module internally faulty
- PossibleSoftware of throttle module and ECM do not match
- RareLow or unstable supply voltage
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.