SRS - Wiring Harness Installation

CATEGORY: Electrical

SECTION: 3

PAGE: 75

ISSUE: 08/94-0494

CODE: 371

Subject:
Installing Wiring Harness for SRS System

Application:
1989-1994 9000 Models

To repair a recurring complaint of the SRS lamp being lit, or when the harness has been damaged, separate spare part wiring harnesses have now been made available. Because the SRS system wiring harness should never be spliced, minor collision damage could result in the need to replace the entire main wiring harness. The new separate wiring harnesses were produced to simplify repairs and make them less expensive. When you fit the new harnesses, the old should be left in place.

These harnesses are designed specifically to repair problems that generate Diagnostic Trouble Codes (DTC's) OE S, OF S, 10 S, 11 S, 12 S, 13 S, 14 S, 23A24, 23A25, 25321, 25322, 25341 and 25342. Follow the steps below to install the hamesses. Also be certain you have reviewed the diagnostic procedures in Service Manual 8:6 Airbag to make certain that it is indeed necessary to replace them.

Cars Affected:

1989-94 9000 models (all)

Parts:

Wiring harness for front sensor (-1991) 44 33 132
Wiring harness for RH seat belt
tensioner (-1991) 44 33 140
Wiring harness for front sensors (1992-94) 44 33 165
Wiring hamess from 4-pin connector to
RH front sensor (1992-94) 46 63 035
Wiring harness for LH seat belt tensioner
(1992-94) 44 33 181
Wiring harness for RH seat belt tensioner
(1992-94) 44 33 173

Tools (See Figure 2):

Removal tool 85 80 110

Removal tool (round pins) 30 14 230

The last four points of the warning above eliminate the need to wait 20 minutes before detonating the airbag after disconnecting the battery as pointed out in the "Safety and handling instructions" section of the Service Manual 8:6 Airbag.

If a connector is unplugged while the ignition is switched on, the control module will record it as a fault. The "fault" will not disappear until the connector is plugged in again and the DTC cleared.

-M91

Wiring harness for front sensors, P/N 44 33 132

1. Remove the cover over the false bulkhead space and remove the partition.
2. Remove the insulating material from under the dashboard on the left and right sides.
3. Stick a piece of tape over the pins on the loose ends of the wiring harness to protect them.
4. Position the spare parts wiring harness in the engine bay. The branch should be ahead of the rubber grommet in the bulkhead at A in the illustration. The shorter lead (B) is for the LH front sensor and the longer lead (C) is for the RH front sensor.
5. Remove the cover over the cable conduit beside the battery and place the wiring harness in the conduit.
6. Remove the washer fluid reservoir and lift up the front main fuse box in the engine bay. Run the wiring harness under the main fuse box and along to the LH front sensor. Fasten with cable ties.
7. Remove the old wiring harness connector from the LH front sensor and fasten it back in a suitable place by means of a cable tie.
8. Plug the new wiring harness into the front sensor and use a cable tie to fasten the cable about 10 cm away from it.
9. Fit the wiring harness for the RH front sensor in the rubber grommet on the LH side of the bulkhead.
10. Run the wiring harness behind the front partition at the bottom of the false bulkhead space along to the right-hand side. Be sure to run the cable under existing leads and hoses. Removing the screw and bending out the sheet metal in front of the heating and ventilation unit will make it easier to run the wiring under the unit. Refit the screw.
11. Fasten the wiring by means of cable ties so that it will not get caught up in the wiper arm mechanism.
12. introduce the wiring harness through the rubber grommet in the bulkhead.
13. Run the wiring harness along the RH side of the engine bay along to the RH front sensor. Run it alongside existing leads and hoses. Fasten the wiring at suitable places using cable ties.
14. Remove the old wiring harness connector from the RH front sensor and use a cable tie to fasten it out of the way at a suitable place.
15. Plug the new wiring harness connector into the front sensor.
16. Lift up the main fuse box for the ABS in the engine bay. In the bulkhead above the pedal assembly is a rubber grommet (about 8 cm or 3" dia.).
17. Extract the grommet from inside the cabin and remove the leads.
18. Drill a 010 mm hole in the grommet (predrilled at the rear). Also cut a slit through the grommet to the hole like the slits leading to the other holes.
19. Insert the wiring harness and the old wiring through the rubber grommet from the engine bay side and fit the grommet back in place.

NOTE:
It will be easier to insert the cable if the holes are sprayed with silicone spray. The wiring harness is fitted with shrink tubing at the places where it passes through the rubber grommet.

20. Secure the wiring to the front right-hand comer of the electronics holder and to the air duct above the pedal assembly.
21. Remove the panel on the RH side of the center console and insert the wiring harness. Fasten the wiring harness to the air duct all the way along to the SRS control module. Be sure the harness is clear of the pedals and the steering column.
22. Unplug the SRS control module connector and remove the following pins (using tool P/N 30 14 230):
Pin 1 = GN/RD
Pin 2 = BU/RD
Pin 4 = YE/RD
Pin 10 = GY/WH
Pin 11 = BN/WH
Pin 12 = BK/WH

23. Cut off the pins and wrap insulating tape around the ends of the leads.

24. Fit the spare part wiring harness pins in the connector. Make sure that the differently colored leads are fitted in the pins according to point 22 and as shown in the illustration (Figure 3).
25. Refit all parts that have been removed and clear any diagnostic trouble codes in the SRS control module.

IMPORTANT
Test drive the car and check that the SRS lamp goes out.

-M91

Wiring harness for RH seat-belt tensioner, P/N 44 33 140

1. Remove the lower trim on the B-pillar and detach the seat belt tensioner.
2. Remove the insulating material on the RH side and fold down the forward edge of the RH panel section.
3. Remove the RH sill scuff plate.
4. Unplug the existing seat belt tensioner cable and cut off the connector.
5. Run the new wiring hamess behind the seat belt reel and plug the connector into the tensioner.
6. Place the wiring in the cable conduit, securing it under the other wiring harness in the conduit.
7. Run the wiring harness behind the carpet and along to the SRS control module.
8. Unplug the SRS control module connector and remove the following pins, using P/N 30 14 230:
Pin 5 = BN
Pin 9 = BU

9. Cut off the pins and wrap insulating tape around the ends of the leads.

10. Fit the spare part wiring harness pins in the connector. Make sure that the differently colored leads are fitted in the pins according to point 8 and as shown in the illustration (Figure 4).
11. Refit all parts that have been removed. Clear any diagnostic trouble codes In the SRS control module.

IMPORTANT
Test drive the car and check that the SRS lamp goes out.

M92-94

Wiring harness for front sensor, P/N 44 33 165
1. Remove the cover over the false bulkhead space and remove the partion.
2. Remove the insulating material from under the dashboard on the LH side.
3. Stick a piece of tape over the pins on the loose ends of the wiring harness to protect them.
4. Position the spare part wiring harness in the engine bay. The branch should be ahead of the rubber grommet in the bulkhead at A in the illustration. The lead with the 3-pin connector is for LH front sensor (B) and the lead with the 4-pin connector is for RH front sensor (C).
5. Remove the cover over the cable conduit beside the battery and place the wiring harness in the conduit.
6. Run the wiring harness along to LH front sensor (B).
7. Remove the old wiring harness connector from the LH front sensor and fasten it back in a suitable place by means of a cable tie.
8. Plug the new wiring harness into the front sensor and use a cable tie to fasten the cable about 10 cm away from it.
9. Fit the wiring harness for the RH front senor in the rubber grommet on the LH side of the bulkhead.
10. Run the wiring harness behind the partition at the bottom of the bulkhead space along to the right-hand side.
Be sure to run the cable under existing leads and hoses. Removing the screw and bending out the sheet metal in front of the heating and ventilation unit will make it easier to run the wiring under the unit. Refit the screw.
11. Fasten the wiring by means of cable ties so that it will not get caught up in the wiper arm mechanism.
12. Unplug the existing 4-pin connector and plug in the new wiring harness connector.
13. Lift up the main fuse box for the ABS in the engine bay. In the bulkhead above the pedal assembly is a rubber grommet (about 8 cm or 3" dia.). A hole is prepunched in the sound insulating mat to accept the grommet.
14. Extract the grommet from the cabin side and remove the leads.
15. Drill a 10 mm dia. hole in the grommet (predrilled at the rear). Also cut a slit through the grommet to the hole just like the slits leading to the other holes.
16. Insert the wiring harness and the old wiring through the rubber grommet from the engine bay side and fit the grommet back in place.

NOTE:
It will be easier to insert the cable if the holes are sprayed with silicone spray. The wiring harness is fitted with shrink tubing at the places where it passes through the rubber grommet.
17. Use cable ties to secure the wiring to the front right-hand corner of the electronics holder and to the air duct above the pedal assembly.
18. Remove the panel on the RH side of the center console and insert the wiring harness. Use cable ties to fasten the wiring harnesses to the heating and ventilation unit and air ducts. Be sure the harness is clear of the pedals and steering column.
19. Unplug the SRS control module connector and remove the following pins using tool P/N 85 80 110:
Pin 7 = YE/RD
Pin 8 = GN/RD
Pin 26 = BU/RD
Pin 9 = GY/WH
Pin 10 = BK/WH
Pin 27 = BN/WH

20. Cut off the pins and wrap insulating tape around the ends of the leads.

21. Fit the spare part wiring harness pins in the connector. Make sure that the differently colored leads are fitted in the pins according to point 19 and as shown in the illustration (Figure 5).

Check that the pins are locked firmly in place by pulling lightly on each lead.

22. Refit all the parts that have been removed. Clear any DTC In the SRS control module.

IMPORTANT
Test drive the car and check that the SRS lamp goes out.

M92-94

Wiring harness between the 4-pin connector and RH front sensor, P/N 46 63 035

1. Unplug the connector from the RH front sensor.
2. Run the wiring along the RH side of the engine bay.

Use cable ties to fasten the wiring harness at suitable places.

3. Remove the cover over the false bulkhead space.

4. Fit the wiring harness in the rubber grommet and run it out to the bulkhead space on the RH side.
5. Unplug the 4-pin connector on the RH side of the bulkhead space.
6. Plug the new wiring harness for the RH front sensor into the 4-pin connector.
7. Refit all parts that have been removed. Clear any DTC's in the SRS control module.

IMPORTANT
Test drive the car and check that the SRS lamp goes out.

M92-94

Wiring harness for LH seat belt tensioner, P/N 44 33 l81

1. Remove the lower trim on the B-pillar and detach the seat belt tensioner.
2. Remove the insulating material on the LH side and fold down the forward edge of the RH panel section.

Also remove the LH sill scuff plate.

3. Unplug the existing seat belt tensioner cable and cut off the connector.
4. Run the new wiring harness behind the seat belt reel and plug the connector into the tensioner.
5. Place the wiring in the cable conduit, securing it under the other wiring harness in the conduit.
6. Follow the air duct along to the SRS control module and fasten it by means of cable ties.
7. Unplug the SAS control module connector and remove the following pins using tool P/N 85 80 100:

Pin 4 = BN
Pin 5 = BU

8. Cut off the pins and wrap insulating tape around the ends of the leads.

9. Fit the spare part wiring harness pins in the connector. Make sure that the differently colored leads are fitted in the pins according to point 7 and as shown in the illustration (Figure 7).

Check that the pins are locked firmly in place by pulling lightly on each lead.

10. Refit all parts that have been removed. Clear any DTC's in the SRS control module.

IMPORTANT
Test drive the car and check that the SRS lamp goes out.

M92-94

Wiring Harness for RH seat belt tensioner, P/N 44 33 173

1. Remove the lower trim on the B-pillar and detach the seat belt tensioner.
2. Remove the insulating material on the RH side and fold down the forward edge of the RH panel section.
3. Remove the RH sill scuff plate.
4. Unplug the existing seat belt tensioner cable and cut off the connector.
5. Run the wiring harness behind the seat belt reel and plug the connector into the tensioner.
6. Place the wiring in the cable conduit, securing it under the other wiring harnesses in the conduit.
7. Run the wiring harness behind the carpet and alongside the center console up to the SRS control module.
B. Unplug the SRS control module connector and remove the following pins using tool P/N 85 80 110:
Pin 23 = BU/WH
Pin 24 = YE/WH

9. Cut off the pins and wrap the insulating tape around the ends of the leads.