What does code P2AAB mean?

DTC codes / P2Axx · Hybrid propulsion / P2AAB

P2AABEngine Coolant Bypass Valve B Position Sensor Circuit Intermittent/Erratic

P2AAB means the engine computer has detected an intermittent or erratic signal from the position sensor inside the engine coolant bypass valve B. The bypass valve routes coolant around the radiator to speed warm-up, and the computer needs a steady sensor reading to command the valve accurately; a signal that cuts in and out or jumps around triggers this code.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaHybrid propulsion

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.