P0521

P0521

Diagnosis information - DME (DFI)

Oil pressure sensor implausible

NOTE:
- The engine oil pressure is set by the oil pressure-regulating valve.
- The oil pressure depends on:
- Oil temperature
- Engine speed

- If the oil pressure is outside a defined range, a fault is detected:
- at engine speed < 1,000 rpm --> required pressure < 6.2 bar
- at engine speed > 3,008 rpm --> required pressure > 1.5 bar
- The measured oil pressure is compared with the ambient pressure in the control unit after-run phase (after ignition off) --> required value < 0.5 bar difference.

Diagnostic conditions
- Engine idling > 1 minute, then:
- Engine speed > 3,010 rpm, then:
- Ignition off and ignition key removed for > 1 minute

Possible fault causes
- Oil pressure too low
(oil level, oil pump, dirt in oil circuit, oil circuit faulty, etc.)
- Oil pressure sensor faulty (incorrect trimming compared with ambient pressure sensor)