C05A5ABS Pump Motor Supply Voltage B Circuit/Open
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- 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.
- What you may notice
- ABS/ESC or brake system warning on
- Reduced pressure build-up or loss of redundancy message
- Likely causes
- LikelyBlown fuse or fusible link in the B supply
- PossibleOpen wire or loose terminal in the B feed to the brake unit
- RareInternal fault in the second power stage of the brake module
- Repair
- Medium · Usually a job for a workshop.Typical cost: €20 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.