Network, generic

U0308 Software Incompatibility With Throttle Actuator Control Module

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

U0308 flags that the throttle actuator control module carries software or a calibration that the engine controller does not accept. In most current cars throttle control lives inside the ECM/PCM, so a separate TAC module and this code are rare; no manufacturer documents U0308 publicly. Ford shows how such a mismatch is handled when the logic is integrated: its 2012 OBD summary files a software version mismatch between the electronic-throttle processors under U0300, non-MIL on Gen2 and MIL on Gen3/Gen4 throttle systems. GM's U03xx procedure links these codes to a module that was not configured after installation. Throttle control affects emissions, so CARB demands monitoring and a MIL is likely. U0107 means lost contact, U0408 invalid data.

Likely causes

Throttle or engine control module replaced or flashed without matching software
Wrong or outdated calibration loaded, e.g. by an engine tune
Programming aborted due to low voltage

Symptoms

  • Check engine light on
  • Reduced power or limp mode with limited throttle opening
  • Code appears after module replacement or programming

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–700
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

throttle actuator control moduleengine control modulecontrol module software

Related codes

U0107U0408U0301U0300

References: saabwisonline.com, http:, law.cornell.edu, en.wikipedia.org.