C05A5 code meaning
ABS Pump Motor Supply Voltage B Circuit/Open
What C05A5 means
Supply B is a second power feed for the pump motor of the brake unit; C05A5 reports it as missing or open. A second feed is found where the motor or its drive is built redundantly. Hyundai Mobis patents a brake motor with two windings, each with its own power module and own supply input from the battery; if one side fails it is shut off and the other carries the full current. Ipgate describes a brake-by-wire drive with two three-phase strands and electronics on two redundant voltage supplies. No maker documents C05A5 publicly. Mitsubishi's 2023 Outlander PHEV shows the usual single-feed layout: 60 A fusible link to the motor, 10–16 V at the connector. Feed A has its own code C052F. Depending on design, the pump runs on with reduced power or brake functions are cut back.
C05A5 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.3 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C05A5
- ABS/ESC or brake system warning on
- Reduced pressure build-up or loss of redundancy message
Common causes of C05A5
- Most likelyBlown fuse or fusible link in the B supply
- PossibleOpen wire or loose terminal in the B feed to the brake unit
- Less likelyInternal fault in the second power stage of the brake module
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 bFuse
What each part of C05A5 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| A5 | The exact fault in that area. |
What to do next
- Note C05A5 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 C05A5
What does C05A5 mean?
C05A5 means "ABS Pump Motor Supply Voltage B Circuit/Open". Supply B is a second power feed for the pump motor of the brake unit; C05A5 reports it as missing or open. It is a generic code, so it means the same on every make.
Is it safe to drive with C05A5?
Drive gently and only to a workshop. With C05A5 the car can go into limp mode (reduced power) to protect itself.
Will C05A5 fail an emissions test?
C05A5 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 C05A5 to fix?
Difficulty: medium. A typical repair takes 0.3 to 3 hours of work. This is a job for a workshop.
Will C05A5 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.