P0E77
Coolant Bypass Valve B Control Circuit/Open
The coolant bypass valve B reports a control circuit/open condition.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: medium
Common causes
Ordered by how often each turns out to be the cause.
- Open in control wireCommon
- Coil openPossible
- Pin pushed back out of connector bodyLess likely
Parts involved
- Coolant Bypass Valve B
- Wiring Harness
P0E77 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.