OBD-II code · Powertrain (generic, extended)
P2681 Engine Coolant Bypass Valve A Control Circuit / Open
The controller cannot drive the engine coolant bypass valve A. The valve usually routes coolant around the radiator during warm-up; without it warm-up takes longer and emissions during the warm-up phase rise.
Is it safe to drive with P2681?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen coil in bypass valve solenoid
- PossibleBroken control wire
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–3.5 h
- Emissions test
- Likely to fail
- Parts involved
- Coolant Bypass Valve A, Solenoid, Wiring Harness
Related codes
- P26ACEngine Coolant Bypass Valve B Control Circuit / Open
- P26B7Engine Coolant Bypass Valve C Control Circuit / Open
- P26BDEngine Coolant Bypass Valve D Control Circuit / Open
- P267EB Rocker Arm Actuator Position Sensor Circuit Intermittent/Erratic Bank 2
- P267FControl Module Internal Temperature Sensor A Circuit Intermittent/Erratic
- P2680Coolant Degassing Valve Control Circuit High
- P2682Engine Coolant Bypass Valve A Control Circuit Low
- P2683Engine Coolant Bypass Valve A Control Circuit High
- P2684Actuator Supply Voltage C Circuit / Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.