OBD-II code · Powertrain (generic)
P0652 Sensor Reference Voltage B Circuit Low
Same as P0651 with the reference rail shorted to ground. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
Is it safe to drive with P0652?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyReference rail shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- Check engine light on
- Possible limp mode or no-start
- Multiple follow-up faults across modules
- Reset/relearn may be needed after repair
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Sensor Reference Voltage B
Related codes
- P0698Sensor Reference Voltage C Circuit Low
- P06A4Sensor Reference Voltage D Circuit Low
- P06D3Sensor Reference Voltage E Circuit Low
- P06D7Sensor Reference Voltage F Circuit Low
- P262DSensor Reference Voltage G Circuit Low
- P064FUnauthorized Software or Calibration Detected
- P0650Malfunction Indicator Lamp Control Circuit Malfunction
- P0651Sensor Reference Voltage B Circuit Open
- P0653Sensor Reference Voltage B Circuit High
- P0654Engine RPM Output Circuit Open
- P0655Engine Hot Lamp Output Control Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.