C0004
TCS Control Channel B Valve 2
Fault on traction control system control channel B valve 2.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: hard
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Valve stuck or coil failedCommon
Parts involved
- Tcs Valve B2
C0004 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.