Installation of Zae II Control Module (P/N 65 77 8 369 828): Overview

Special Procedures:
Service Action # 152

Situation:





A. 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.

B. Additionally, ZAE II evaluates the exact equipment level installed on the vehicles 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








E36 Vehicles

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).