Electrical - Various Electrical Failures While Driving

SI B61 16 08
General Electrical Systems

December 2011
Technical Service

This Service Information bulletin supersedes SI B61 16 08 dated November 2008.

[NEW] designates changes to this revision

SUBJECT
N51 SULEV (PZEV) - JBE Repeat Failures Due to Shorted Fuel Sender Harness

MODEL
E90, E92, E93 PZEV: 328i, 328Ci, 328 CiC with N51

SITUATION
The customer may complain about various electrical system failures which occurred while driving:

^ A/C stopped working

^ Fuel gauge display is implausible (shows empty)

^ Rear windows "one-touch" function is inoperative

^ Windshield wipers are working without being switched on

^ Various warning lights are illuminated on the instrument cluster

During the course of diagnosis, several fault codes are detected in the JBE (Junction Box Electronic) module:

^ A6E5/A6E4 (Fuel sensor signal plausibility)

^ 9C5E (A/C refrigerant sensor signal)

^ A72A/A72B/A72C/A72D (Rear window Hall sensor signal)

^ 9C69 (Rear stratification potentiometer)

[NEW] Also, fuel sensor plausibility faults may be stored in the DME (2DE4/2DE5) and in the Kombi (9319/931A).

[NEW] The JBE module shows signs of local overheating.

[NEW] Additionally, the vehicle's warranty history reveals multiple repair attempts for the above-listed complaints. The JBE module was previously replaced; the wiring harness and body ground connections were checked without finding a root cause.

CAUSE

Possibly, the right side fuel sending unit ground wire is intermittently shorted to the B+ terminal of the electric fuel pump inside the fuel tank.

As a result, the battery voltage, traveling via the fuel sender ground path, overloads the ground circuits of the JBE, causing its failure.














[NEW] PROCEDURE





PARTS INFORMATION








[NEW] WARRANTY INFORMATION