P15A6

What the Code Means

P15A6 maps to BMW factory fault 2F7A: the oil pressure sensor reads implausibly high before the engine starts — more than 400 mbar above atmospheric pressure. Before every start, the DME runs a plausibility check: with the engine off, oil pressure must equal atmospheric pressure. If the sensor sends an elevated value, the module logs the fault. Severity is minor.

Symptoms

• The oil pressure warning light does not come on.
• A slight increase in fuel consumption.
• Possible abnormal whine (howl) from the oil pump.

Diagnosis and Repair

The procedure follows BMW factory fault 2F7A:

1. Check the oil pressure sensor ground wire.
2. Inspect the sensor wiring and connector for corrosion and damage.
3. Test the oil pressure sensor itself.
4. Clean the contacts if they're dirty; replace the sensor if it's faulty.

The typical cause of this code is not real overpressure but a bad signal from a poor ground contact or a failed sensor, so start diagnosis with the wiring.

Secondary Damage

• The oil pump may run in overdrive (excess output).
• Engine bearing damage if the fault is ignored.

Severity is rated minor, but don't put off checking the lubrication system: the consequences above are expensive to fix.