OBD-II code · Chassis
C05A7 ABS Pump Motor Supply Voltage B Circuit Low
ABS pump motor supply B below expected range. 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 C05A7?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyWeak supply or high resistance
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Repair at a glance
- Difficulty
- Easy
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.3–2 h
- Emissions test
- Usually unaffected
- Parts involved
- ABS Pump Supply B
Related codes
- C05A4Wheel Speed Sensors Supply Circuit Low
- C05A5ABS Pump Motor Supply Voltage B Circuit/Open
- C05A6ABS Pump Motor Supply Voltage B Circuit High
- C05A8ABS Pump Motor Supply Voltage B Circuit Range/Performance
- C05A9ABS Pump Motor Supply Voltage Circuit A/B Correlation
- C05AAABS Pump Motor Temperature Too High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.