Powertrain
generic / SAE
P26B1
Engine Coolant Bypass Valve A Stuck Closed
The coolant bypass valve A is stuck closed. Coolant cannot bypass the radiator during warm-up so warm-up takes longer and emissions in the warm-up phase rise.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number6 / B1
Possible causes
- Valve seized closed by debris high
- Actuator linkage jammed in closed position medium
- Carbon or debris buildup preventing free movement low
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 80–600 €
- Estimated time: 0.5–2.5 h
- Component: coolant bypass valve a
- Component: thermostat housing
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012