P2B49B Camshaft Position Actuator Position Sensor B Circuit Low 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
- With P2B49 the module reads too low a signal from position sensor B at the exhaust camshaft actuator of bank 1. A short between signal line and ground, a sensor with an internal short or a missing feed are the usual suspects. The nearest public manufacturer reference is P34BE on the Mercedes M176/M177: the sensor of exhaust solenoid 1 for CAMTRONIC, bank 1, described as shorted to ground. For P2B49 itself no manufacturer document is available. GM sets the comparable exhaust code of its L3B (P2C14) when the driver is on and the circuit shows at most 0.5 Ω to ground. Chafe points on the harness running along the cylinder head cover are worth checking first. Exhaust bank 1 high fault: P2B4A.
- What you may notice
- Check engine light on
- Exhaust cam lift change switched off
- Occasionally further sensor codes
- Likely causes
- LikelySignal line shorted to ground
- PossibleSensor shorted internally
- RareSensor feed missing
- 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.