OBD-II code · Network
U0689 Lost Communication With Turbocharger/Supercharger B Temperature Sensor
The vehicle bus reports loss of communication with smart turbocharger B temperature sensor. Turbo overheat protection switches to a model-based estimate.
Is it safe to drive with U0689?
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
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Turbo B Temp Sensor, Vehicle Bus Wiring
Related codes
- U0643Lost Communication With Turbocharger/Supercharger A Temperature Sensor
- U0686Lost Communication With Catalyst Temperature Bank 2 Sensor 1
- U0687Lost Communication With Catalyst Temperature Bank 2 Sensor 2
- U0688Lost Communication With Throttle Position Sensor/Switch G
- U068ALost Communication With Barometric Pressure Sensor C
- U068BLost Communication With Turbocharger/Supercharger Inlet Pressure Sensor A
- U068CLost Communication With Turbocharger/Supercharger Inlet Pressure Sensor B
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.