C055B: ABS Pump Motor Supply Voltage Circuit A Low
ABS pump motor supply voltage A below expected range.
What C055B means
C055B is a generic OBD-II chassis code in the ABS & brakes group. In plain English: the computer found an electrical fault in that circuit: an open, short or bad connection, or a failed component.
- Check engine light
- Usually on
- Emissions-related
- No
- Limp mode possible
- Yes
- Drive cycle to clear
- Not required
Get it fixed
Post this code once and get quotes from local mechanics. Free to post.
Makes the repair and parts links below specific to your car. Kept in this browser only.
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
- 01Weak battery or supply resistanceMost likely
Can I drive with C055B?
Drive carefully and get it checked soon.
Normal hydraulic braking usually still works, but ABS, stability control or brake assist may be off. Leave extra stopping distance, especially on wet or icy roads. If the pedal feels soft or the red brake light is on, stop driving.
Why we rate it urgent
- ABS or brake assist may be disabled
- Can put the vehicle in limp mode (reduced power)
- Turns on the check engine light
Severity is our rule-based rating from the code’s flags in OBDex and the system it affects, not an inspection of your car. If the check engine light is flashing, or you notice overheating, low oil pressure, or brake or steering problems, stop driving and get help.
How to diagnose C055B
- 1
Confirm the code and save freeze-frame data
Read the codes with an OBD-II scan tool and note every code, not just C055B. Save the freeze-frame data (speed, load, temperature when the fault set) before clearing anything; it tells you when the fault happens.
- 2
Fix other faults first
If other codes are stored, start with power-supply, sensor-circuit and communication codes. They can cause this code as a side effect.
- 3
Test the circuit
Inspect the wiring and connector at the abs pump motor supply a for damage, corrosion or chafing. With a multimeter, check supply voltage, ground and signal against the specifications in the service manual for your vehicle.
- 4
Test the likely causes in order
Start with the most likely cause and work down: Weak battery or supply resistance. Test before replacing parts.
- 5
Check for recalls and service bulletins
Look up recalls for your exact vehicle with its VIN, and ask a dealer about technical service bulletins (TSBs). Manufacturers sometimes issue software updates or extended warranties for known faults.
- 6
Clear the code and verify the repair
After the repair, clear the code and drive the car under the conditions in the freeze-frame data to confirm it does not return.
C055B repair cost estimate
Estimate, not a quote. Labor times are typical ranges for this code from OBDex, and $125/hr is an assumed rate. Shop rates and labor times vary by vehicle and region. Diagnosis time may be billed separately.
- DIY difficulty
- Easy
- Good DIY job?
- Yes, with a scan tool
Basic hand tools; a common first DIY job.
Parts and systems involved
- ABS pump motor supply A
C055B FAQ
What does C055B mean?
C055B means “ABS Pump Motor Supply Voltage Circuit A Low”. ABS pump motor supply voltage A below expected range.
Is C055B serious? Can I keep driving?
We rate C055B as urgent severity. Drive carefully and get it checked soon. Normal hydraulic braking usually still works, but ABS, stability control or brake assist may be off. Leave extra stopping distance, especially on wet or icy roads. If the pedal feels soft or the red brake light is on, stop driving.
What causes C055B?
The most common causes, from most to least likely: Weak battery or supply resistance. Test before replacing parts, because several causes can set the same code.
How much does it cost to fix C055B?
Typical labor is about $40–$250 at an assumed $125/hour shop rate, plus parts. That is an estimate, not a quote: labor times and rates vary by vehicle and region, and diagnosis may be billed separately.
Can I fix C055B myself?
DIY difficulty is easy. Many owners can handle it with a scan tool, a multimeter and basic hand tools. Always confirm the cause before buying parts.
Will C055B clear itself?
If the fault was intermittent, the warning may go off once the computer stops seeing it, but the code stays in memory. Fix the cause; clearing the code alone doesn’t repair anything.