Instrument Panel - Chart to Help Diagnoise Faults

Group 62
Instruments



Bulletin Number
62 05 90 (3081)



Woodcliff Lake, NJ
June 1990
Service Engineering



SUBJECT:
Instrument Cluster before Redesign (before 01/89)

MODELS:
5 Series (E34) and 7 Series (E32) (all so equipped)

Situation:
A high percentage of instrument cluster circuit boards returned under warranty exhibit no faults when tested.

In order to reduce the rate of circuit boards and coding plugs replaced in error, the enclosed decision chart has been prepared.

Note:
This chart is not intended to eliminate the use of the diagnosis and troubleshooting manual. It is intended only to assist with fault evaluation of the instrument cluster. In all cases, the BMW Diagnostic Module, Diagnostic Manual, and Electrical Troubleshooting Manual must be used for an accurate diagnosis.

General
Information:
The enclosed chart is used as follows:

A) Locate "fault" in lefthand column.
B) Perform testing, repairing, or replacing as indicated by marks in the vertical columns.

Special
Notes:






The communication between the coding plug and the instrument cluster circuit board is very complex. There is currently no method of testing a coding plug at the dealership level.

Because of this limitation, please observe the following procedures when this troubleshooting chart or other diagnostic materials indicate the possibility of a faulty coding plug:

1. If all other possible causes of the fault have been tested and found good or repaired, replace the coding plug.

2. If the fault is not corrected, do not leave the replacement coding plug installed. Remove it and reinstall the original coding plug.

3. Replace the instrument cluster circuit board (only after installing original coding plug).



These procedures must be followed to determine whether the coding plug is faulty, or the circuit board is unable to read and use the coding plug programming.


Any questions regarding warranty coverage should be discussed with your District Service Manager.