OBD-II code · Network
U0628 Lost Communication With A/C Refrigerant Pressure Sensor B
The vehicle bus reports loss of communication with smart A/C refrigerant pressure sensor B. Compressor cycling and high/low pressure protection cannot use this input.
Is it safe to drive with U0628?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
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
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- AC Refrigerant Pressure Sensor B, Vehicle Bus Wiring
Related codes
- U0626Lost Communication With A/C Refrigerant Pressure Sensor A
- U0625Lost Communication With Fuel Rail Pressure Sensor Bank 1
- U0627Lost Communication With A/C Refrigerant Temperature Sensor A
- U0629Lost Communication With A/C Refrigerant Temperature Sensor B
- U062ALost Communication With A/C Refrigerant Distribution Valve Actuator A
- U062BLost Communication With A/C Refrigerant Distribution Valve Actuator B
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.