A/T - Torque Converter Clutch Engagement, EPROM: Overview

9232bmw02

Group 24
Automatic Transmission


Bulletin Number
24 09 91 (3327)


Woodcliff Lake, NJ
May 1992
Product Engineering


This Service Information Bulletin supersedes S.I. 24 09 91 (3327) dated September 1991. It includes additional part numbers for the '92 Models. Please remove and discard S.I. 24 09 91 (3327) dated September 1991 from your S.I. binder.

SUBJECT:
Torque Converter Clutch Engagement

MODELS:
1991 and 1992 535iA, 735iA, 750iL, and 850iA produced before 2/92

Situation:
Customers may complain of excessive cycling on and off of the torque converter clutch or early engagement which causes the sensation of a lugged engine at certain speed ranges with light to medium throttle application. An additional complaint may be the sensation of the transmission freewheeling when coasting downhill.

Solution:
A transmission control module EPROM is available with revised mapping of the converter clutch engagement. The converter clutch will now stay engaged when coasting. This is the only change that has been made to the program.

This revised mapping has been phased into production beginning 2/92. 1992 models having an original transmission control module WITHOUT the revised mapping can be identified by the following BMW Numbers when calling up the Transmission Control Module (EGS) Identification page on the 2013 or MoDiC (updated transmission control modules will have the same BMW Numbers, but can be identified by the "BMW NA Quality Control" label affixed to the control module's cover):





'92 Transmission Control Module Identification (Without Revised Torque Converter Clutch Mapping)


Note:
Do not install this new transmission control module EPROM into a 750 or 850 which does not have the latest EML control module software (Software Numbers F32, D32, or S32). Refer to S.I. 12 03 91 (3326) for additional information on these EML software updates.


The instructions detail the procedure for EPROM replacement.





Parts
Information:
Early '92 vehicles may have the same transmission control module version as '91 models. Verify control module version and order the EPROM based on control module version.





A label with the phrase "BMW NA QUALITY CONTROL" will be automatically included with each EPROM ordered. For purposes of identifying modified transmission control modules, this label must be applied to the front of the control module.


Spare parts are NOT UPDATED. In the rare event that it is necessary to replace a transmission control module which has previously received this modification, it will be necessary to update the replacement part before installation to prevent a reoccurence of the customer's complaint.

Warranty
Information:
Covered under the terms of the BMW New Car Limited Warranty.

Defect code: 24 61 00 12 NA

Description Labor Operation Model FRU

R & R Control Module 24 61 500 E32/E34 3

E31 2

Exchange EPROM 24 00 000 ALL 2