OBD-II code · Network
U0677 Lost Communication With Fuel Level Sensor B
The vehicle bus reports loss of communication with smart fuel level sensor B. Tank gauge may freeze and low-fuel warnings may be incorrect.
Is it safe to drive with U0677?
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
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Fuel Level Sensor B, Vehicle Bus Wiring
Related codes
- U0676Lost Communication With Fuel Level Sensor A
- U0678Lost Communication With Fuel Level Sensor C
- U0674Lost Communication With Wastegate Position Sensor B
- U0675Lost Communication With Turbocharger/Supercharger Speed Sensor A
- U0679Lost Communication With Transmission Fluid Pressure Sensor/Switch A
- U067ALost Communication With Transmission Fluid Pressure Sensor/Switch B
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.