OBD-II code · Network
U0424 Invalid Data Received from HVAC Control Module
The HVAC Control Module is present on the data bus but the values it reports are implausible — out of range, frozen, or failing the checksum or rolling-count check. The receiving modules reject the data. Automatic climate control behaves erratically. Causes include a faulty sensor feeding the module, internal computation errors, a software or calibration mismatch after a repair, or bus interference corrupting the frames.
Is it safe to drive with U0424?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- PossibleHVAC module internal fault
- PossibleCAN corruption causing checksum errors
- Less likelyGateway module routing CAN messages incorrectly
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
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Usually unaffected
- Parts involved
- HVAC Control Module, Can Bus Wiring
Related codes
- U0421Invalid Data Received from Throttle/Pedal Position Sensor
- U0422Invalid Data Received from Body Control Module
- U0423Invalid Data Received from Information Center
- U0425Invalid Data Received from Vehicle Immobilizer Control Module
- U0426Invalid Data Received from Vehicle Immobiliser Control Module
- U0427Invalid Data Received from Vehicle Security Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.