SRS - Warning Lamp ON/DTC's 8 or 9 Set
SI B72 05 00Safety Restraint Systems
January 2005
Technical Service
This Service Information bulletin supersedes S.I. 72 05 00 dated September 2000.
[NEW] designates changes to this revision
SUBJECT
Side Airbags Resistance too High; Fault Codes 8/9 (MRS2), or Fault Codes 05/06 (MRS3)
MODEL
E46 produced up to 02/00
SITUATION
The SRS airbag warning light stays illuminated and fault codes 8 or 9 (in MRS 2 system), or hex codes 05 or 06 (in MRS 3 system) - "Side airbag, resistance too high" are stored in the Airbag Control Module memory.
CAUSE
Carbon contamination on the ignition circuit connection pins, at the door A-pillar connector.
[NEW] PROCEDURE
Connect DISPlus/GT1 tester to a vehicle and read out MRS module fault memory. If the above faults are stored, replace the airbag plug connector terminals in the respective A-pillar connector as follows:
1. Disconnect vehicle 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. Remove the side trim in the footwell on the affected A-pillar (refer to Repair Instructions RA 51 43 070 (left) or RA 51 43 075 (right)).
3. Remove the door wiring harness connector from the A-pillar and unplug the connector.
4. To disassemble the vehicle side of the connector, release securing tabs on both sides and slide out the blue locking plate.
5. Remove the pins 19 and 20 from the connector (pins 19 and 20 are located at the bottom of the connector - brown and blue twisted pair of wires).
Using a small screwdriver carefully press on pin's locking tab, while at the same time gently pulling out a wire from the connector.
Attention:
The AMP connector housing has two locking steps, for that reason the pin's locking tab must be depressed twice.
6. 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.
7. 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.
8. Crimp butt connectors (1) to each of the wires.
9. Re-twist the two wires together so that the twist runs up to the bull connector.
10. Shorten the pair of airbag wires in the "Repair cable for A, B-pillar/control unit" to a suitable length to attach from the A-pillar connector, to the vehicle-side wiring harness previously prepared with butt connectors. Strip 4 mm at the ends of the wires.
11. 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.
12. Re-twist the wires. Note that the untwisted length must not exceed 40 mm.
13. Insert the terminals into locations 19 and 20 in the connector housing sockets previously vacated.
14. Using electrical tape, tape up the harness to hold the repaired wires in place.
15. Remove the door trim panel.
16. To disassemble the door-side part of the connector, release securing tab located on the side (as shown on the illustration).
17. Then slide out the housing assembly.
18. Remove pins 19 and 20) from the connector housing, and cut off the contacts.
19. Tie back the cables remaining on the wiring harness (door side) with electrical tape.
20. Route the twisted repair cable "Repair cable for A, B-pillar/side airbag" through the rubber grommet and into the inside of the door. Tip: It is easier to thread the cable through if you use a piece of wire as a tool.
21. Install the two terminals on the repair cable into the connector housing (positions 19 and 20). 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 of an adequate length.
22. Using wire ties, secure the repair cable to the door wiring harness and route it to the side airbag. Identify a suitable point where the repair cable can be spliced into the original harness.
23. 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.
24. Crimp butt connectors (1) to each of the wires.
25. Re-twist the two wires together so that the twist runs up to the bull connector.
26. Shorten the pair of airbag wires in the "Repair cable for A, B-pillar/side airbag" 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.
27. 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.
28. Using electrical tape, tape up the harness to hold the repaired wires in place.
29. Tie back any remaining cut wires with electrical tape.
30. Reinstall the removed parts. Note: Do not use Stabilant 22A on the connectors.
31. Clear the airbag control unit fault memory.
PARTS INFORMATION
WARRANTY INFORMATION
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