C055B code meaning
ABS Pump Motor Supply Voltage Circuit A Low
What C055B means
Supply voltage A of the pump motor is below its lower limit. Under load the motor pulls the feed down, so a weak 12 V battery, a corroded terminal, a high-resistance fusible link or a poor ground can all set it, and the relay may chatter. No maker publishes C055B. On the 2023 Outlander PHEV Mitsubishi specifies 10–16 V at the motor feed and flags an ignition supply of 10 V or less at its brake unit within 1 s under C1056-16, a code without generic equivalent. A patent originally filed by AlliedSignal and now owned by Bosch flags its own fault if the motor sits under roughly 7 V at shut-off, and a Hitachi patent for electric brake actuators limits motor current once the vehicle supply falls under a set level. Charge and test the battery before replacing parts.
C055B at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyEasy, DIY possible
- Typical labor0.2 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C055B
- ABS and ESC warning lamps on, often after cold starts
- Pump runs sluggishly or ABS functions drop out
Common causes of C055B
- Most likelyWeak or discharged 12 V battery
- PossibleCorroded terminal or high-resistance fusible link in the motor feed
- PossiblePoor ground connection of the ABS unit
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
ABS pump motor supply a
What each part of C055B means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5B | The exact fault in that area. |
What to do next
- Note C055B and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about C055B
What does C055B mean?
C055B means "ABS Pump Motor Supply Voltage Circuit A Low". Supply voltage A of the pump motor is below its lower limit. It is a generic code, so it means the same on every make.
Is it safe to drive with C055B?
Drive gently and only to a workshop. With C055B the car can go into limp mode (reduced power) to protect itself.
Will C055B fail an emissions test?
C055B is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is C055B to fix?
Difficulty: easy. A typical repair takes 0.2 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will C055B clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.