P2B4EB Camshaft Position Actuator Position Sensor B Circuit High Bank 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2B4E closes the group: the exhaust-side position sensor B of bank 2 sends a signal above its upper limit. Usually the sensor ground is open, the signal line is shorted to a supply, or the sensor is faulty. No manufacturer explains P2B4E publicly; the NTN-SNR code list only gives outlet sensor B, second bank, signal too high. In the CAMTRONIC family Mercedes uses on the M176/M177, the sensor is part of the actuator, so a confirmed sensor fault means a new actuator. Until then the engine runs on the fixed default cam profile on that bank, which mostly shows as a lit warning lamp and slightly more fuel use. CARB requires such circuit faults to be detected. Bank 1 counterpart: P2B4A.
- What you may notice
- Check engine light on
- Bank 2 runs on the default cam profile
- Slightly higher fuel use
- Likely causes
- LikelySensor ground open
- PossibleSignal line shorted to a supply
- PossibleSensor faulty (actuator replacement)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €650
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.