A/T - Cannot Engage Drive Or Reverse
SI B25 02 07Gear Shift Mechanism
April 2011
Technical Service
This Service Information bulletin supersedes SI B25 02 07 dated December 2008.
Similar information may be found in Service Information bulletin SI B24 19 07 dated December 2008.
[NEW] designates changes to this revision
SUBJECT
Diagnostic for GWS Faults - Drive Position "D" Cannot Be Engaged
MODEL
[NEW] E60, E61 with 6HP19TU or 6HP26TU transmission
[NEW] Vehicles produced from 03/01/07 to 06/09/08
[NEW] E63, E64 with 6HP19TU or 6HP26TU transmission
[NEW] Vehicles produced from 09/01/07 to 06/09/08
SITUATION
The customer complains that after the engine has started or during parking maneuvers, the drive position "D" (or reverse "R") cannot be engaged using the GWS (Gear Selector Switch), especially at low ambient temperatures.
[NEW] In some cases, ISTA (Integrated Service Technical Application) vehicle test finds fault codes ("currently not present") stored in the GWS Gear Selector Switch (A838, A830, A82A), or in the EGS transmission control module (51AB).
None of the customer's complaints can be reproduced in the workshop or during test drives.
CAUSES
1. The customer is not familiar with GWS operation (incorrect driver usage).
2. In certain cases, there may be a possible hardware fault in the GWS shifter.
CORRECTION
The following fault code descriptions provide helpful diagnostic hints when dealing with GWS-related complaints on E6X 6HP19TU/6HP26TU equipped vehicles:
^ A838 "Play protection blocking active": This fault is set when a lock button is pressed and released numerous times (more than 20 times during a 40 second time period with KL15 on). After the fault is set, the locking function does not work - the shifter can be moved forwards and backwards without pressing the unlock button. D or R is not engaged. The transmission stays in Park.
^ A830 "Resetting system faulty": This fault is set if the GWS shifter cannot return from the steptronic gate (left position) to the middle position when P is selected. The main reason for this fault is a mechanical blockage. If the shifter is being manually held to the left while the P button is pressed, after five return attempts the A830 fault will be set with the P indicator flashing. Also, this fault may occur under extreme environmental conditions: extremely high or low ambient temperatures; under voltage conditions; or due to incorrect installation (excessive pressure from the shift gate bezel on the shifter disc).
^ A82A "Parking button faulty": This fault is set when the P button is pressed very slowly, and/or the button is not fully depressed.
^ 51AB "EGS incorrect signal from GWS: P button": A fault is stored in the EGS module when the GWS fault code A82A was present (see above). Continue diagnosis in the GWS shifter test plan.
If all four faults are stored, then there is a strong indication that the customer is not fully familiar with the GWS operation strategy. For example, when performing a "three point turn" parking maneuver, the customer needs to move the GWS shifter from the steptronic gate (if driving in the sport or manual mode) to the center position prior to engaging the R or D gears. In such a situation, the customer needs to be advised on the proper operation of the GWS shifter.
Important Note:
Please remind the customer that the drive position D or R gear request from the GWS shifter will be ignored (the transmission will stay in Park) if the driver's door is not fully closed and the driver's seat belt is not latched. Also, if the driver were to leave the vehicle with the engine running with drive position D or R selected, the automatic transmission would automatically shift into the park position P.
This is a built-in safety feature of the EGS/GWS, not a system malfunction.
[NEW] When diagnosing any GWS-related complaint or fault, always perform all applicable steps of the ISTA test plan module B5116_GWSPER_E6.
[NEW] The GWS should be replaced when prompted by the ISTA test plans, and after careful evaluation of the all GWS faults stored. After GWS replacement, the complete vehicle needs to be reprogrammed and recoded, using the current version of ISTA P.
The latest improved GWS shifters can be identified by production date code 8241 or later.
The date code format is 8=year, 16=week, 4=day
PARTS INFORMATION
WARRANTY INFORMATION