OBD-II code · Powertrain (generic, extended)
P2AA8 Engine Coolant Bypass Valve B Position Sensor Range/Performance
The engine coolant bypass valve B position signal does not match plausibility checks against related signals. Sensor drift.
Is it safe to drive with P2AA8?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor characteristic drifted
- PossibleSensor mounting displaced from reference path
- Less likelySensor element aged beyond calibration window
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
- P2AA5EGR Cooler Bypass Control Circuit Driver Current/Temperature Too High Bank 1
- P2AA6EGR Cooler Bypass Control Circuit Driver Current/Temperature Too High Bank 2
- P2AA7Engine Coolant Bypass Valve B Position Sensor Circuit
- P2AA9Engine Coolant Bypass Valve B Position Sensor Circuit Low
- P2AAAEngine Coolant Bypass Valve B Position Sensor Circuit High
- P2AABEngine Coolant Bypass Valve B Position Sensor Circuit Intermittent/Erratic
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.