Transmission Control Module Fault Code 40 (24 06 94 (4134))

TRANSMISSION CONTROL MODULE FAULT CODE 40

TECHNICAL SERVICE BULLETIN

SUBJECT

Transmission Control Module Fault Code 40

SITUATION

"Trans Program" is displayed in the matrix (E34) or the transmission fault indicator is illuminated (E36). Cycling of the ignition switch restores normal operation. Fault code 40 - Pressure Regulator, is stored in the fault memory of the transmission control module. The setting of Fault Code 40 occurs very intermittently and may not be "currently present" at the time the vehicle is being diagnosed.

CAUSE

The pressure regulator monitoring circuitry of the control module is too sensitive and may cause Fault Code 40 to be set erroneously.

CORRECTION

The pressure threshold values in the latest EPROMs have been changed to eliminate the erroneous setting of fault code 40. The EGS control module EPROM is to be replaced if it is determined that FC 40 has been set erroneously.

PROCEDURE

Prior to the replacement of any components perform the following:

1. - Check fault memory of EGS for existence of fault code 40.
2. - If fault code 40 is "currently present" in the EGS control module and confirmed to be non intermittent, (i.e. cycling of the ignition switch does not change fault status) check the resistance between the following pins with the ignition switched off and the control module not connected:
   RESISTANCE MEASUREMENTS
   
   

   Pin Locations	Ohmmeter Reading	Action
   Pin 40 and 41	2-6 Ohms	If value is not obtained replace the pressure regulator.
   Pin 40 and 37	infinite (OPEN)	If value is not obtained check for short to B+.
   Pin 40 and 19	infinite (OPEN)	If value is not obtained check for short to ground.

3. - If fault code 40 is not "currently present" replace the EPROM in the transmission control module. Please refer to TECHNICAL SERVICE BULLETIN 24 05 95 for complete instructions on exchanging the transmission control module EPROM.
4. - The replaced EPROM can be identified by a new Software Number being displayed on the EGS identification screen of the service tester:
   REPLACEMENT EPROM INFORMATION
   
   

   P/N of Replacement EPROM	New Software Number
   01 00 1 469 120	3337633311
   01 00 1 469 121	3337633316
   01 00 1 469 123	3337633013
   01 00 1 469 124	3337633315
   01 00 1 469 125	3337633614
   01 00 1 469 126	3337630820
   01 00 1 469 127	3337633014
   01 00 1 469 128	3337633215
   01 00 1 469 129	3337633615
   01 00 1 469 811	3337633528

   NOTE: THE EPROMS LISTED ABOVE PERTAIN TO VEHICLES EQUIPPED WITH SHIFT LOCK. Vehicles produced prior to 9/91 may not be equipped with a shift lock solenoid. If the vehicle does not have shift-lock (the range selector switch can be removed from park or neutral without depressing the brake pedal) please contact the Technical Service Hotline in order to obtain a replacement Service EPROM.

PARTS INFORMATION

The updated transmission control module EPROM can be ordered by the following part numbers based on model and production range:

WARRANTY INFORMATION

Parts and labor will be reimbursable under the terms of the applicable BMW New Car Limited Warranty.