This TSB relates to water leaking into the electronics box on E70, E71 and E72 BMW models produced from 10-1-06 up to 1-22-10.
Any of the following situations could occur if water has entered the electronics box:
* The engine is hard to start or will not start.
* The engine goes into emergency mode operation.
* The battery is discharged.
* Various Check Control messages are displayed.
* Various DME faults are stored or the DME is not recognized in an ISTA diagnostic session.
Water inside the electronics box could result in damage to the DME/DDE module and wiring plug-in contacts. Check for water egress into the electronics box. If water is present, the following steps must be carried out to determine the necessary repairs.
Begin by removing the right front cowl components and the electronics box lid.
1. Visually inspect the vehicle wiring harness for damage to the sheathing, including the underside, in the area where it enters the electronics box (1), back down to where the harness is secured to the inner fender housing (2).
2. Visually inspect the seal for the electronics box lid for damage.
3. Visually inspect the correct seating of the harness grommets in the electronics box.
4. Check the harness plug contacts for evidence of oxidation or the presence of moisture.
5. Check the operation of the electronics fan (if fitted).
1. Re-wrap the wiring harness sheathing using adhesive tape, up and over the grommet and back, in both directions so that the tape overlaps. The repeat the process using fabric tape, securing the end of the fabric nearest the inner fender housing (2) with a wire tie.
2. Wipe dry the electronics box (removal or replacement is not necessary).
3. If the seal in the lid is damaged, replace it. Otherwise, it can be re-used.
4. If there is evidence of moisture or oxidation on the plug-in contacts, they must be cleaned or replaced.
5. Seat the harness grommets back into the electronics box. Carefully fit the box lid. Secure the three clips and close the slide lock.