SRS - Warning Light ON/Fault Codes 16/17 Stored
GROUP 72Safety Restraint Systems
72 04 00
Woodcliff Lake, NJ
May 2001
Service Engineering
This Service Information bulletin supersedes S.I. 72 04 00 dated June 2000.
SUBJECT
Sensors for Side Airbags, MRS 3 Fault Codes 16/17
MODEL
Z3 roadster, Z3 coupe, M roadster, M coupe (E36/7)
produced from 04/99 up to 05/00
SITUATION
The SRS airbag warning light stays illuminated, and fault codes 16 or 17 - "Sensor for side airbag, Coding data do not correspond to equipment. Currently not present" are stored in the Airbag Control Module memory.
CAUSE:
Communication between the MRS 3 module and the satellite sensor has been disturbed by electromagnetic interference in the vehicle's electrical system.
CORRECTION:
In case of customer complaint, use DIS/MoDiC tester to diagnose the MRS 3 system. If the SRS fault code description stored in the control module exactly matches the faults listed above, then proceed as follows:
1. Utilizing the "Control Unit Identification" function of DIS/MoDiC, check the part number of the airbag control unit. If an airbag control unit with PN 65 77 8 386 192 is installed in the vehicle, it must be replaced with the improved part - PN 65 77 6 908 896 (refer to "PROCEDURE I" for replacement instruction).
2. Inspect the connector (X74) of the airbag control module. The satellite sensors harness (pin 20 - white/blue wire, and pin 21 - white/yellow wire at connector X74) should consist of twisted pair of wires. In case impact sensors wires are not twisted pair, they have to be replaced with the "Side airbag sensor repair kit" - PN 61 10 6 914 295 (refer to "PROCEDURE II" for installation instruction).
3. In case the correct airbag control module (PN 65 77 6 908 896) is installed, and the satellite sensors harness consist of twisted pair of wires, then replace the affected side airbag satellite sensor - PN 65 77 6 905 454 (refer to TIS Repair Instruction 65 77 550 for replacement procedure).
PROCEDURE I
(To replace and recode MRS 3 control module):
1. Remove vehicle's center console in order to gain easy access the MRS control module.
Refer to repair instruction 51 16 200 for removal and installation procedure.
DO NOT remove the old control unit at this time.
2. Connect diagnostic connector to the vehicle. CD 25 (or higher) should be loaded into DIS/MoDiC tester.
3. Turn the key on (KL15).
4. Select "Coding/Program."
5. Select "3. ZCS Coding". Scroll right >.
6. "Coding by means of central coding code (ZCS) Version C25" is displayed. Scroll right >.
7. "ZCS encoding can be overwritten by the modifications made by the CAR/KEY MEMORY program. They can be reset if necessary" is displayed. Scroll right >.
8. Select the engineering series E36. Scroll right >.
9. Select "1. Recoding". Scroll right >.
10. Select "19. AIRBAG". Scroll right >.
11. Select "1. Replace control unit". Scroll right >.
12. "First read data out of faulty control unit and save. Then transfer data to new control unit and code control unit" is displayed. Scroll right >.
13. Select "1. Read data out of faulty control unit". Scroll right >.
14. "Is a faulty ABG control unit still fitted in the vehicle?" is displayed. Select "YES".
15. "Turn on ignition! Start reading the data" is displayed. Select "YES".
16. "Install new control unit. Then transfer data to new control unit and recode control unit. The data is stored in the tester" is displayed. Scroll left <.
17. Turn the ignition OFF. Disconnect battery. Replace the original MRS Control Module with the improved one (PN 65 77 6 908 896). Reconnect battery, turn ignition ON.
18. Select "2. Transfer data to new control unit and code control unit" is displayed. Scroll right >.
19. "Enter the last 7 places of the chassis number" is displayed. Scroll right >.
20. After entering the last 7 digits of the VIN, "Confirm input/identification" is displayed. Select "YES".
21. "Install control unit, turn on ignition" is displayed. Scroll right >.
22. "Transfer data to new control unit and start automatic coding?" is displayed. Select "YES".
23. "AIRBAG automatic coding active! Please wait!" is displayed.
24. When coding is complete, "AIRBAG The central coding code has not been changed! Coding Complete! Turn ignition off. Wait 10 seconds. Turn ignition on again and carry out the functional check" is displayed.
25. The MRS module coding is now complete.
26. Clear the fault memory in the airbag control unit.
PROCEDURE II
(To install side airbag sensor repair kit):
1. Disconnect battery.
2. Remove the inner entrance cover strips on the left and right side of the vehicle.
Refer to TIS Repair Instruction 51 47 000 for removal procedure.
3. Remove left and right side seats. Refer to TIS Repair Instruction 52 10 000 for removal procedure.
4. Remove the center console. Refer to TIS Repair Instruction 51 16 200 for removal procedure.
5. Fold carpet towards front of the vehicle.
6. Unplug and tie back the two connectors (4) from the satellite sensors (5).
7. Plug the connectors from the "Side airbag repair kit - PN 61 10 6 914 295" (1) into the satellite sensors (observe the corresponding marks - left/right on the repair kit for the left-hand and right-hand sensor).
8. Route the harness under the carpet, towards airbag control unit (as indicated by a dotted line). Fix the routed wires with adhesive tape (2) and existing cable ties (3).
9. Unplug connector X74 (1) from the airbag control unit (2). Release connector from its housing.
10. Unpin, insulate and tie back two wires from position 20 (white/blue wire), and position 21 (white/yellow wire) of connector X74.
11. From the "Side airbag repair kit", plug the yellow wire (3) into position 21, and the blue wire (4) into position 20 of connector X74.
12. Reassemble X74 connector, and plug it into the airbag control module.
13. Attach the 0-ring connector (1) of the airbag repair harness (together with ground connector 2) to the airbag unit mounting stud (use 8.8 Nm torque to tighten the nut).
14. Reconnect the battery.
15. Clear the fault memory in the airbag control unit.
16. In order to verify correct installation of the "Side airbag repair kit", disconnect one of the satellite sensors. Turn ignition ON, and from the airbag control unit fault memory read the stored fault code. Make sure that the indicated fault corresponds to the disconnected satellite sensor.
17. Reconnect satellite sensor, and clear fault memory in the airbag control module.
18. Reinstall all removed components.
PROCEDURE III
To replace/recode MRS3 control module, and install a "Side airbag repair kit" please refer to Procedures I and II.
PROCEDURE IV
(For replacing satellite sensor):
Refer to Repair Instruction 65 77 550 ("Removing and installing/replacing satellite sensor for left or right side airbag") found in BMW TIS.
PARTS INFORMATION
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty.
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