This is a review of common Code on E46 SMG pump that are due to failure of pump to provide correct system pressure.
54 (0x36) Exceeding pressure range
This error code will present itself when pressure sensor signal states system pressure is too high and cannot be controlled back within specification even when pump is de-energized.
There are a number of factors that can lead to this, most common problem in order of failure.
1-High power relay(salmon relay) is damaged.
Over time the relay will become unreliable and not follow DME instructions by either staying in an ON or OFF position. this could trigger two specific codes based on bellow.
- When stuck in ON position it will cause smg pump to keep running continuously and eventually overheat and burn out SMG pump motor. (this could also Triger 54(0x36) error code to be stored)
- When stuck in OFF position it will cause smg pump to not prime to build up required pressure. (This could Triger 53(0x35) error code to be stored)
2-Defective pressure sensor will cause an incorrect system pressure reading to DME.
3-Wiring harness damage, This could occur if relay is stuck ON overheating wire harness and damaging insulation causing pump to keep running contionously.