Instruments - Cluster Replacement Decision Chart

90BMW21 Group 62 Instruments
Bulletin Number 62 07 90 (3152)
Woodcliff Lake, NJ November 1990 Service Engineering
SUBJECT: Instrument Cluster Redesign (from 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.

Instrument Cluster Redesign:

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, replace the instrument cluster circuit board using the original coding plug. Do not leave the replacement coding plug installed in the new circuit board.
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.