P2B4E: B Camshaft Position Actuator Position Sensor B Circuit High Bank 2

What it means

The position sensor B of the camshaft position actuator on the exhaust side of bank 2 reports a circuit high condition. Cam phasing position cannot be measured reliably.

At a glance

• Usually lights the check-engine light
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

Position sensor B measures the exhaust cam actuator position on bank 2. The engine control module monitors its electrical signal and sets this code when that signal is abnormally high, preventing reliable tracking of bank 2 exhaust cam phasing.

Common causes

Most likely first.

1. Signal wire shorted to B+
2. Open position sensor
3. Connector pins corroded - high contact resistance

Symptoms

• Check engine light on
• Power loss especially in mid-rpm range
• Possible rough idle or stalling
• Increased fuel consumption

How to diagnose it

1. Record freeze-frame data and compare live readings from bank 2 exhaust actuator sensor B with the commanded cam position.
2. Inspect the sensor B connector and harness on bank 2 for damage, corrosion, loose pins, and contact with a battery power wire.
3. Check the sensor signal, reference, and ground circuits using the vehicle wiring information for opens or poor connections.
4. With the sensor disconnected as specified by service information, check whether the signal wire is shorted to battery voltage.
5. If the harness checks pass, test the bank 2 exhaust actuator position sensor B against the manufacturer's specification.

Common fixes

• Clean and secure corroded or loose bank 2 sensor connector terminals.
• Repair a signal wire shorted to battery voltage or an open in the circuit.
• Replace a failed bank 2 exhaust actuator position sensor B.
• Clear the code and confirm the measured position follows commanded position.

Can I keep driving?

Avoid hard acceleration and high engine speeds because bank 2 exhaust cam timing may not be measured reliably, and power can fall. If rough running or stalling occurs, stop driving until the engine runs consistently.