C0003TCS Control Channel B Valve 1
- Generic OBD-II code · Chassis
- Can trigger limp mode
- How the car detects it
- C0003 is the counterpart of C0001 in channel B, the second brake circuit of the modulator. A pump patent for such units shows the layout plainly: two normally open isolation valves and two normally closed priming valves, one of each per circuit, operated by the control unit alongside the apply and release valves when traction control intervenes. Valve 1 of channel B therefore matches the first valve of the other circuit; the published sources do not fix which function carries the number. A coil open or short, a current outside the expected window or a pressure that fails to follow the command sets the code. Traction and stability control are disabled and the warning lamp lights, while ordinary braking is unaffected. No manufacturer documents this code publicly.
- What you may notice
- ABS warning lamp on
- Traction and stability control disabled
- Normal braking retained without ABS
- Likely causes
- LikelySolenoid coil open or shorted
- PossibleCorroded or chafed wiring to the modulator
- RareInternal hydraulic modulator fault
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €300 – €1,600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.