OBD-II code · Network
U066B Lost Communication With Turbocharger/Supercharger Bypass Valve B Position Sensor
The vehicle bus reports loss of communication with smart turbocharger bypass valve B position sensor. Closed-loop control loses its actual feedback.
Is it safe to drive with U066B?
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
- 0.5–3 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Turbo Bypass Valve B Position Sensor, Vehicle Bus Wiring
Related codes
- U0657Lost Communication With Turbocharger/Supercharger Bypass Valve A Position Sensor
- U0668Lost Communication With Engine Oil Level Sensor Circuit
- U0669Lost Communication With EGR Sensor D
- U066ALost Communication With EGR Sensor E
- U066CLost Communication With Exhaust Heat Exchanger Bypass Valve Actuator B
- U066DLost Communication With Charge Air Cooler Temperature Sensor Bank 1
- U066ELost Communication With Charge Air Cooler Temperature Sensor Bank 2
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.