OBD-II code · Network
U02AB Lost Communication With Vehicle Thermal Management Control Module
The vehicle bus reports loss of communication with the vehicle thermal management module. Coordination of engine, battery and cabin cooling/heating loops is lost; sub-modules fall back to local control.
Is it safe to drive with U02AB?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyBus wiring open or shorted
- PossibleModule without power or ground
- PossibleModule failed
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Thermal Management Module, Vehicle Bus Wiring
Related codes
- U02A8Lost Communication With Engine Sound Control 2
- U02A9Lost Communication With Charge Air Cooler Coolant Pump A
- U02AALost Communication With Engine Disconnect Clutch
- U02ACLost Communication With Turbocharger/Supercharger Boost Control A
- U02ADLost Communication With Turbocharger/Supercharger Boost Control B
- U02AELost Communication With Hybrid/EV Battery Coolant Pump
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.