U0104Lost Communication With Cruise Control Module
- Generic OBD-II code · Network
- How the car detects it
- U0104 names the cruise control module, today usually the radar unit of adaptive cruise control that sends speed and distance requests to the engine. GM's 2019 truck ECMs check its frames $2CB and $2CD, treat gaps beyond 500 ms that persist for 3 s as a failure and classify the result as Type C, emissions-neutral and without MIL; detection pauses while the bus-off code of the carrying bus (U0073, U0074) is active. Saab's 2011 9-4x code list carries U0104 with sub-codes for short to ground, invalid data, wrong message counter and checksum error. While the code is active, cruise or distance control switches off or cannot be armed; driving and emissions are unaffected. U0405 covers implausible data from this module.
- What you may notice
- Cruise or adaptive cruise unavailable, warning message
- Forward collision alert may switch off as well
- No MIL
- Likely causes
- LikelyRadar/cruise module without power or with a wet, loose connector (front bumper area)
- PossibleFront-end damage or bumper repair affecting module or wiring
- PossibleDamaged CAN lines to the module
- RareCruise/radar module internally faulty
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.