Fuel System - Misfire DTC's, Crank-No Start, Power Loss

SI B12 21 10
Engine Electrical Systems

September 2010
Technical Service

SUBJECT
Service Engine Soon Lamp Illuminated: Loss of Power and Various Faults are Stored in the DME

MODEL
E90, E92 and E93 (3 Series) with N51 engine from start of production

SITUATION
The customer complains that the service engine soon lamp is illuminated. The vehicle has lost power, engine cranks but will not start and various faults are stored in the DME for engine misfire.

CAUSE
The vehicle has lost fuel system delivery pressure due to a loose or split fuel line inside the fuel tank. The failure is related to an unfavorable stacking of tolerances between the rubber fuel hose and the plastic regulator nipple or deterioration of the rubber hose construction material.

PROCEDURE

1. Check the fuel pressure as per Repair Instruction REP 13 31 029 Checking the fuel pump delivery pressure.

2. If no fuel pressure is present then remove the right side fuel tank access cover to inspect the fuel hose (1) for disconnection or damage. Refer to Repair Instruction REP 16 14 010 Removing and installing the fuel pump.





IMPORTANT:
For the clarity of the picture, this is a photo of a fuel tank removed from the vehicle. Do not remove the fuel tank for the hose inspection.





3. Inspect the fuel hose connection (1) on the pressure regulator (2). If the fuel hose is found to be disconnected from the fuel pressure regulator, replace the fuel tank. Do not attempt to replace or re-secure the fuel hose inside the fuel tank.





4. Inspect the fuel hose (1) for splitting. It might be necessary to inspect the entire circumference of the fuel hose with a small mirror. If the fuel hose (1) is found to be split, replace the fuel tank. Do not attempt to replace or re-secure the fuel hose inside the fuel tank.

5. If neither of these conditions is found, continue diagnosis using the available ISID test plans for the faults stored in the DME before submitting a DMTL System TC case.

Note:
TeileClearing authorization is not required for the fuel tank replacement procedure described in this bulletin. Please write in the comment section of the warranty claim: "Replaced per SI B12 21 10".





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WARRANTY INFORMATION