P2B4AB Camshaft Position Actuator Position Sensor B Circuit High Bank 1
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2B4A says the position sensor B signal of the bank 1 exhaust camshaft actuator is above its limit. An interrupted sensor ground, a short to a voltage source or a failed sensor are typical. No manufacturer describes P2B4A publicly, and the Mercedes CAMTRONIC bulletin does not include any high fault of this family. As a comparison only, GM checks the exhaust sliding-cam circuits of the 2.7-litre L3B for an unwanted link to supply voltage with the output switched off (P2C15, 0.5 Ω, 4 of 5 samples, Type A). The engine module keeps the exhaust lift system in its safe position until the fault is gone. CARB counts such sensors among the comprehensive components that need circuit monitoring. Exhaust low fault on bank 1: P2B49.
- What you may notice
- Check engine light on
- Exhaust lift system kept in safe position
- Usually unchanged driveability
- Likely causes
- LikelySensor ground interrupted or connector corroded
- PossibleSignal line shorted to a voltage source
- PossibleSensor failed
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.