OBD-II code · Powertrain (generic, extended)
P26A4 Engine Coolant Bypass Valve A Position Sensor Circuit
The position sensor on the coolant bypass valve A returns no usable signal. Closed-loop control of bypass position is lost.
Is it safe to drive with P26A4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen sensor element
- PossibleCorroded sensor connector
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.8–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Bypass Position Sensor A, Wiring Harness
Related codes
- P23C3Engine Coolant Bypass Valve C Position Sensor Circuit
- P2AA7Engine Coolant Bypass Valve B Position Sensor Circuit
- P26A1Exhaust Aftertreatment Glow Plug Circuit Low
- P26A2Exhaust Aftertreatment Glow Plug Circuit High
- P26A3Engine Coolant Bypass Valve A Range/Performance
- P26A5Engine Coolant Bypass Valve A Position Sensor Circuit Range/Performance
- P26A6Engine Coolant Bypass Valve A Position Sensor Circuit Low
- P26A7Engine Coolant Bypass Valve A Position Sensor Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.