U012BLost Communication With Chassis Control Module B
- Generic OBD-II code · Network
- How the car detects it
- U012B is the counterpart to U012A for a second chassis controller, labelled B. No manufacturer documents U012B in an openly available source, so its exact job (air suspension, damping, steering or another chassis task) depends on the vehicle. Logic follows the usual network rule that CARB requires and GM spells out for module A: a receiving controller expects a periodic message, and if it stays away for a calibrated time while supply and ignition are valid, the receiver stores the code for the silent partner. GM's tables for U012A list Type B on engine nodes and Type C on the transmission, so the warning lamp behaviour is maker specific. Invalid data from module B is U042C.
- What you may notice
- Chassis warning message in the cluster
- Functions handled by module B (e.g. suspension) unavailable
- Scan tool cannot reach module B
- Likely causes
- LikelyFuse, power or ground of chassis module B interrupted
- PossibleDamaged bus line or connector to module B
- RareChassis module B internally faulty or not programmed
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.