Updated Transmission Control Module EPROM (24 03 93 (3763))
Publication date: 1993-04-01Reference number: 24 03 93 (3763)
UPDATED TRANSMISSION CONTROL MODULE EPROM
TECHNICAL SERVICE BULLETIN
| BMW: | 740iA/iL |
| GROUP: | 24 - Automatic Transmission |
SUBJECT
Updated Transmission Control Module EPROM
COMPLAINT
"Trans Program" displayed on the instrument cluster matrix display AND fault code 100 or 105 stored in the transmission control module.
or
Harsh 1-2 l upshift and what some customers may describe as an excessive amount of gear changes, both up and down.
CAUSE
Due to normal production tolerances in the transmission, each clutch has slightly different fill times and friction characteristics. The parameters on the original transmission control module EPROM may not allow the control unit sufficient time to adapt to the individual transmission's characteristics before logging a fault.
CORRECTION
An updated EPROM is available for the transmission control module which will solve the above complaints. Control modules which already have the updated EPROM may be identified by calling up the Identification page of the transmission control module using the BMW Service Tester or MoDiC and checking the control module Serial Number; Serial Number C2729X or greater identifies the control module as having the latest EPROM.
The transmission control module must be left disconnected from the wiring harness for at least 60 minutes after exchanging the EPROM as this will ensure that any previously stored adaptation values are erased. As the amount of time required for adaptation to occur has been increased, please be advised that installation of the EPROM and a quick trip around the block will most likely not be sufficient to provide a proper evaluation of the new software. In exceptional cases, depending on the number of shifts, it may be necessary to accumulate 50-100 miles of driving for proper evaluation of the new software.
PROCEDURE
Please reference the attachment for complete instructions on exchanging the transmission control module EPROM.
PARTS INFORMATION
The updated transmission control module EPROM may be ordered under the following part number:
| Part Number | Description |
|---|---|
| 01 00 1 467 938 | 740iA/iL EGS EPROM |
WARRANTY INFORMATION
Covered under the terms of the BMW New Car Limited Warranty.
| Defect Code | Labor Operation | Labor Allowance |
|---|---|---|
| 24 61 001 2 00 | 24 61 501 - Remove and Install control module | 2 FRU |
| 24 61 001 2 00 | 24 00 000 - Exchange EPROM | 2 FRU |
ATTACHMENT TO S.I. 24 03 93 (3763)
TRANSMISSION CONTROL MODULE EPROM EXCHANGE INSTRUCTIONS
PREPARATORY INSTRUCTIONS
The installation of the updated EPROM into the Transmission Control Module is a simple procedure.
However, before beginning the EPROM exchange, the following conditions must be provided and the designated tools must be used.
- ENVIRONMENT
The work area where the EPROM is exchanged must be free of excessive dust and aggressive chemicals or vapors. A small uncarpeted office within the dealership is recommended. Since low atmospheric humidity promotes static electricity, an evaporating bowl of water can be used to raise the humidity level of the work area. - EQUIPMENT
Screwdrivers (blade type) are only used to open and close the Control Module. The EPROM is exchanged using an IC extractor/inserter set. Tool sets can be obtained locally (Radio Shack, Archer #276-1581). - STATIC ELECTRICITY
The Transmission Control Module can be damaged and rendered unusable by static electrical discharge. For this reason the 3M static protection kit (or equivalent) must be used during the entire EPROM exchange procedure. See TECHNICAL SERVICE BULLETIN 04 30 87 (1546) for complete details. - EPROM STORAGE
Replacement EPROMs must be stored in the original shipment containers. The label in the center of the EPROM must never be removed.
PROCEDURE
- Lay the control module face down on the static mat and remove retaining pin from middle plastic rivet using needle nose pliers. See Fig 1 .
- Remove the 2 screws (Torx T20) from the top side of the control module. See Fig 2 .
- Carefully bend the 6 tabs up on the cover (bottom side of the control module) only as far as necessary to remove the cover. See Fig 3 .
- Remove cover from the control module.
- Remove the white plastic cover from the top side of the control module.
- Carefully separate the two circuit board support towers. Gently raise the rear of the upper circuit board and fold the connecting ribbon out between the two circuit boards. See Fig 4 .
- While gently raising back of upper circuit board, release the two front retaining clips in the connector plug. See Fig 5 .
- Slide the circuit board backwards out of the connector and rotate upwards. Lay the open control module out on the static mat. See Fig 6
.
This procedure is easiest to perform if the back of the circuit board is raised and a slight downward pressure is exerted on the connector pins of the upper circuit board.
- With the upper circuit board removed, remove the EPROM security cap by inserting a small straight blade screwdriver into the slot on each long side and releasing the catch by gently prying outward against the side. See Fig 7 and Fig 8 .
- Remove EPROM from circuit board using the IC extractor tool. See Fig 9
.
CAUTION: Do not touch the contact pins of the EPROM.
- Install the new updated EPROM using the IC inserter tool. See Fig 10
.
The EPROM is correctly installed when the notch in the EPROM aligns with the notch in the IC socket.
Assure that all the EPROM contact pins are fully inserted by pushing down on the EPROM until the stop is felt.
- Reinstall EPROM security cap.
- Reinstall upper circuit board and place white plastic cover on top.
- Reinstall cover with 2 Torx screws and bend tabs down.
- Affix "BMW NA Quality Control" label onto front of control unit for future identification of modification to control unit. Label will be included with order.