OBD-II code · Powertrain (generic, extended)
P2AAA Engine Coolant Bypass Valve B Position Sensor Circuit High
Voltage on the engine coolant bypass valve B position sensor signal line is above the expected window. Wire shorted to B+ or sensor open.
Is it safe to drive with P2AAA?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySignal wire shorted to B+
- PossibleOpen sensor
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- Parts involved
- Engine Coolant Bypass Valve B Position Sensor, Wiring Harness, Ecm
Related codes
- P23C5Engine Coolant Bypass Valve C Position Sensor Circuit High
- P26A7Engine Coolant Bypass Valve A Position Sensor Circuit High
- P2AA7Engine Coolant Bypass Valve B Position Sensor Circuit
- P2AA8Engine Coolant Bypass Valve B Position Sensor Range/Performance
- P2AA9Engine Coolant Bypass Valve B Position Sensor Circuit Low
- P2AABEngine Coolant Bypass Valve B Position Sensor Circuit Intermittent/Erratic
- P2AACDiesel Fuel Presence Sensor Circuit
- P2AADDiesel Fuel Presence Sensor Range/Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.