Error code
OBD2 U0409
OBD2U0409
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.
What it means
Invalid Data Received From Alternative Fuel Control Module.
Severity
moderateCan be driven, but may experience performance issues or reduced efficiency.
Summary
U0409 indicates that the car's computer is receiving invalid data from the alternative fuel control module, which manages systems related to alternative fuels like E85 or natural gas.
Common Causes
- Faulty communication between the vehicle’s main computer and the alternative fuel control module
- Malfunctioning alternative fuel control module
Fixes
- Replace the faulty communication component or alternative fuel control module.
FAQ
What does U0409 mean?
U0409 means that there is an issue with data transmission between the vehicle's main computer and the alternative fuel control module.
How do I fix U0409?
Fixing U0409 typically involves diagnosing whether the communication component or the alternative fuel control module itself is faulty, and replacing it if necessary.
Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.
More OBD2 codes
- U0400Invalid Data Received
- U0401Invalid Data Received From ECM/PCM
- U0402Invalid Data Received From Transmission Control Module
- U0403Invalid Data Received From Transfer Case Control Module
- U0404Invalid Data Received From Gear Shift Control Module
- U0405Invalid Data Received From Cruise Control Module
- U0406Invalid Data Received From Fuel Injector Control Module
- U0407Invalid Data Received From Glow Plug Control Module
- U0408Invalid Data Received From Throttle Actuator Control Module
- U0410Invalid Data Received From Fuel Pump Control Module
- U0411Invalid Data Received From Drive Motor Control Module
- U0412Invalid Data Received From Battery Energy Control Module A