Camshaft Position Sensor B Circuit Low (Bank 2)
What it means
The engine computer has seen the signal voltage from camshaft position sensor B on bank 2 stay below its normal limit. This usually points to a wire shorted to ground or a loss of sensor supply, so the computer disables exhaust cam timing control on that bank.
Symptoms4
- Check engine light on.
- Reduced power because bank 2 variable valve timing (VVT) is disabled.
- Occasional long cranking.
- Higher fuel consumption.
Possible causes6
- Signal wire shorted to ground through chafed or burned insulation near the exhaust manifold.
- Open or weak supply voltage to the sensor.
- Internal short inside the sensor.
- Corroded or oil-soaked connector.
- A short in another sensor sharing the same reference voltage supply.
- Faulty engine computer (rare).
How to diagnose5
- Read all codes and look for reference voltage codes such as P0641 or low-voltage codes on other sensors.
- Unplug the sensor, measure supply voltage at the connector and compare it with the manufacturer specification.
- Measure resistance between the signal wire and the body with connectors unplugged.
- Inspect the bank 2 harness for burned or chafed insulation.
- If the circuit is sound, try a known-good sensor or swap it with an identical bank 1 sensor.
How to fix5
- Repair and insulate the shorted section and route the harness away from heat.
- Clean the connector and fix the source of oil reaching it.
- Repair the reference supply circuit or the other sensor causing the short.
- Replace bank 2 cam sensor B if it is proven faulty.
- Clear the codes and confirm the code does not return.
Repair cost
In Saudi riyals; the highlighted part is the expected range for this fault.
The fix is often a simple wire or connector repair; the cost rises when a new sensor is needed in a hard-to-reach location.
Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026
Frequently asked questions
Why do this sensor's wires sometimes burn?
The exhaust cam sensor harness may run near the hot exhaust manifold. If its clips come loose, the insulation melts and the wire shorts to ground.
Does this code harm the engine?
Usually not directly, but it reduces performance and raises fuel use, and backup mode can mask other faults, so repair it soon.
This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.
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