C05AB
Brake Blending Separation Valve Performance
Brake blending separation valve does not respond as expected — used to isolate hydraulic and regenerative brake circuits on EVs/hybrids.
- 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 mechanicallyCommon
Parts involved
- Brake Blending Valve
C05AB 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.