OBD-II code · Powertrain (generic, extended)
P2DE8 Cold Start Engine Coolant Bypass Valve D Stuck Open
During cold start, the engine coolant bypass valve D is stuck in the open position. Coolant bypasses the warm-up loop.
Is it safe to drive with P2DE8?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyValve stuck in open position
- PossibleActuator failed
- Less likelyCarbon or debris buildup preventing free movement
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Engine Coolant Bypass Valve D
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.