SRS - Warning Lamp ON/DTC's 9A4A/9A6B Set
SI B 72 01 05Safety Restraint Systems
February 2005
Technical Service
SUBJECT
Rear Side/Thorax Airbags, Resistance Too High
MODEL
E65/66 (7 Series)
SITUATION
The airbag warning light is permanently lit. The following fault codes are stored in the "rear seat satellite" (SSH) fault memory, indicating a contact fault with high contact resistance.
9A4A - "Resistance, firing pellet, rear right thorax airbag triggering circuit, too high..."
9A6B - "Resistance, firing pellet, rear left thorax airbag triggering circuit, too high..."
CAUSE
High resistance at contacts to respective B-pillar connector.
AFFECTED VEHICLES
Vehicles from start of production until 11/1/2002 only
PROCEDURE
In case of customer complaint, perform diagnosis with DISplus/GTI. Work through the corresponding test module and eliminate the high contact resistance using the repair cables as follows:
1. Disconnect the battery
Caution!
When performing diagnosis or repairs to the airbag system, always follow the "Safety Regulations for Handling Components of the Airbag System" (RA 32 34..).Comply with airbag safety precautions! Incorrect handling can activate airbag and result in injury. Disconnect the vehicle's battery before commencing any repairs.
2. Install the repair cable to the respective door as follows:
^ Remove the door trim from the affected door (refer to Repair Instruction 51 42 000)
^ Remove the door wiring harness (refer to Repair Instruction 61 12 187).
^ Guide the repair cable through the cable protection sleeve towards the B-pillar connector.Note: The plug contacts must not be damaged when doing this. To this end, the connectors are protected by a short plastic hose.
^ Remove and cut off the red (pin 11) and blue/red (pin 12) triggering circuit wires from the B-pillar connector (X273 for left door, X274 for right door). Install corresponding wires from the repair cable to pins 11 and 12 of X273/X274.
^ Reinstall the door wiring harness and the inner door carrier. Cut off the existing connector for the thorax airbag from the door wiring harness.
^ Connect the repair cable connector to the thorax airbag connector (X1781 left door, X1782 right door) and, if necessary, secure the excess length of the repair cable to the door wiring harness with insulating tape.
3. Replace the thorax triggering circuit wires (B-pillar) on the vehicle wiring harness as follows:
^ Remove B-pillar trim to access the B-pillar connector (X273 left side, X274 right side) (refer to Repair Instruction 51 43 150).
^ Remove the yellow/black (pin 11) and yellow/brown (pin 12) thorax triggering circuit wires from the B-pillar connector (X273 for left door, X274 for right door). Cut back the tape on the wiring harness until a suitable area is found to attach butt connectors. This must not be a moving or mechanically stressed area of the wiring harness.
^ In this area, cut through the two airbag wires at points approx. 30 mm offset (A). Untwist the wires to give some working room and strip 4 mm at the ends of the wires.
^ Crimp butt connectors (1) to each of the wires.
^ Re-twist the two wires together so that the twist runs up to the butt connector.
^ Install the two terminals on the repair cable into the connector housing (pins 11 and 12). It is not important in which position each terminal is installed. To ensure that there is no mechanical stress, make the wires on the connector housing an adequate length.
^ Shorten the pair of airbag wires in the "Repair cable for B-pillar" to a suitable length to attach to the side airbag wiring harness previously prepared with butt connectors. Strip 4 mm at the ends of the wires.
^ Install shrink tubing to the open wires, then crimp to the butt connectors. Position the heat shrink over the butt connectors and, using a heat gun, apply heat to seal the connection. Note that the two butt connectors must not be immediately adjacent to each other and that the untwisted length must not exceed 40 mm.
^ Using electrical tape~ tape up the harness to hold the repaired wires in place.
^ Tie back any remaining cut wires with electrical tape
4. Reassemble the vehicle. Reinstall any parts, which have been removed (B-pillar connector, B-pillar trim, door trim, etc.).
5. Connect vehicle battery.
6. Clear the fault memory.
PARTS INFORMATION
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.