P1397
ModerateP1397 — VANOS Solenoid Valve: Malfunction
Description
What the Code Means
Code P1397 points to a fault in the camshaft position sensor B (usually the exhaust side). The sensor sends a signal to the DME for variable valve timing control. The fault can come from contamination, damaged wiring, or a failed sensor.
Symptoms
Symptoms
- Hard starting
- Rough running (misfire, fluctuating idle)
- Loss of power
- Check Engine light on
Causes and fixes
Diagnosis and Repair
- Check the sensor and wiring: inspect the connector and wires for damage, corrosion, or breaks.
- Clean the sensor: remove oil and dirt from the sensor face.
- Replace the sensor: if faulty, fit a genuine OEM BMW part (
11361433772). - Clear the codes: after the repair, erase the fault codes and verify the engine runs correctly.
Possible secondary damage
Secondary Problems
Ignoring the fault can lead to incorrect VANOS operation, which may cause the timing chain to jump and damage the engine. Higher fuel consumption is also possible.