Coding Supplemental Restraint Control Module (ZAE II) (72 05 96)

CODING SUPPLEMENTAL RESTRAINT CONTROL MODULE (ZAE II)

TECHNICAL SERVICE BULLETIN

SUBJECT

Coding Supplemental Restraint Control Module (ZAE II)

SITUATION

1. ZAE II Control Modules will supersede ZAE Control Modules in parts inventory. If a ZAE II Control Module (Part Number 65 77 8 369 828) is installed in an affected vehicle which was originally equipped with a ZAE Control Module (P/N 65 77 8 352 763), the replacement module needs to be coded. This coding will change the Central Coding Key (ZCS) and a new Central Coding Key label must be printed and affixed to the vehicle. See Fig 1 .
   Fig 1: ZAE II Control Module

   
2. Additionally, ZAE II evaluates the exact equipment level installed on the vehicle and compares it with the Central Coding Key. If discrepancies are found, a fault or faults indicating "Encoding data does not match vehicle equipment" will be set in ZAE II memory. These faults can not be cleared and they will set the SRS warning light. In this case the ZAE II connector must be modified.

CAUSE

The original ZAE control module ignores discrepancies between Central Coding Key (ZCS) information and actual "Seat Occupancy Detection" equipment installed (Seat Occupancy Sensor and/or Seat Belt Buckle switch). Such a discrepancy may exist in cases like the following example:

• a vehicle is not originally equipped with all "Seat Occupancy Detection" components
• however, that vehicle is equipped with a wiring harness which includes connections for Seat Belt Buckle switches and/or Seat Occupancy Sensor (SBE)
• a buckle assembly containing a switch is installed during a later service, yet the Central Coding Key still indicates the absence of "Seat Occupancy Detection".

If you install a ZAE II module into such vehicle the discrepancy will cause ZAE II faults to set.

CORRECTION

1. If a ZAE II Control Module is installed in a vehicle produced 9/93 through 6/94 and the message "Central Coding Key changed" appears after automatic coding of the ZAE II Airbag Control Module (P/N 65 77 8 369 828), print a new ZCS Label, cross out the old label, and affix the new label over it.
2. Clear the Fault Memory to eliminate any erroneous faults. Be sure to switch off the ignition for ten seconds before switching it on again.
3. Survey the Fault Memory of the ZAE II Control Module. If any faults are recorded, select each fault individually. When the fault is selected during diagnosis, if the message "Encoding data does not match vehicle equipment" appears below the fault description, examine the "VN" line of the Central Coding Key (ZCS).
4. If the "VN" line of the ZCS indicates that the vehicle is not equipped with Seat Occupation Detection, and faults are stored as described above, the wiring at the ZAE II Control Module connector must be modified according to the following procedure. This coding for Seat Occupation Detection is deciphered as follows:

   E31, E34 Vehicles

   1. If sixth position is "6", vehicle is not coded for Seat Occupation Detection. See Fig 2 . The wiring must be modified.
      Fig 2: VN Line For E31/E34 Without Seat Occupation Detection

      
   2. If sixth position is "E", vehicle is coded for Seat Occupation Detection. See Fig 3 . Do Not modify the wiring. Isolate and correct the fault with the existing wiring.
      Fig 3: VN Line For E31/E34 With Seat Occupation Detection

      

   E36 Vehicles

   1. If seventh position is "6", vehicle is not coded for Seat Occupation Detection. See Fig 4 . The wiring must be modified.
      Fig 4: VN Line For E36 Without Seat Occupation Detection

      
   2. If seventh position is "E", vehicle is coded for Seat Occupation Detection. See Fig 5 . Do Not modify the wiring. Isolate and correct the fault with the existing wiring.
      Fig 5: VN Line For E36 With Seat Occupation Detection

      

Observe all relevant safety information when performing repairs to the Airbag system. Refer to Repair Instructions, Main Group 32, Subgroup 34, and Service Information Bulletin 72 01 95 (4178) .

PROCEDURE

If it is determined that the wiring must be modified, proceed as follows:

1. Disconnect the negative battery cable and cover the end to prevent the connection from being remade. The battery negative terminal must be disconnected whenever connecting or disconnecting the Airbag control module.
2. Disconnect the ZAE II Connector and remove the locking plate as shown in Fig 6 .
   Fig 6: Removing ZAE II Connector Locking Plate

   
3. Remove the connector cover by sliding it off the pin housing as shown in Fig 7 .
   Fig 7: Removing Connector Cover

   
4. Using a fine pointed screwdriver or scribe, depress the locking tab of pin 15 as shown in Fig 8 , and withdraw the wire and pin from the housing.
   Fig 8: Removing Wire & Pin From Housing

   
5. Repeat for pin 8 and pin 12. See Fig 9 .
   Fig 9: Pins Removed From Connector Housing

   
6. Insulate each pin with a small piece of electrical tape as shown in Fig 10 .
   Fig 10: Insulating Pins With Electrical Tape

   
7. Tape the three wires back to the harness away from the connector as shown in Fig 11 .
   Fig 11: Wires Secured To Wire Harness

   
8. Reassemble the cover to the pin housing as shown in Fig 12 .
   Fig 12: Reassembling Cover To Pin Housing

   
9. Reassemble the locking plate as shown in Fig 13 and reconnect the ZAE II Control Module.
   Fig 13: Reassembling Locking Plate To ZAE II Connector

   
10. Reconnect the battery.
11. Connect the DIS Tester to the vehicle and turn ignition ON.
12. Select "Diagnosis."
13. Select "19 Airbag."
14. Select "Expert Mode" and clear Fault Memory. Be sure to switch off the ignition for ten seconds before switching it on again.
15. Select "Read Fault Memory" and confirm that no new faults are stored.

WARRANTY INFORMATION

Parts and Labor are reimbursable under the terms of the BMW New Car Limited Warranty of 4 years/50,000 miles.

Defect Code	Labor Operation	Labor Allowance
Use the Defect Code appropriate to the reason that the Airbag Control Module was replaced.	61 99 000 - WT Operation for Modifying ZAE II Connector Wiring	3 FRU