Engine Controls - Delayed Throttle Response
SI B 28 07 08M Double-clutch Transmission with Drivelogic
June 2009
Technical Service
This Service Information bulletin supersedes SI B12 55 06 dated January 2009.
[NEW] designates changes to this revision
SUBJECT
M3 with M DCT - Complaint of Delayed Throttle Response
MODEL
E90, E92, E93 with S65 and M DCT transmission up to 04/09 production
SITUATION
The customer may complain about delayed throttle response when reaccelerating after a series of downshifts during heavy deceleration (hard braking). This condition is experienced when the transmission is in D or S mode, with the Drivelogic program selected to three or less bars.
No acceleration delay is experienced when the vehicle is driven in the M manual mode.
INFORMATION
During a "rolling stop" situation, which is followed by heavy acceleration demand, the transmission goes through the series of downshifts in order to match the appropriate gear with the high load signal.
The short time period necessary to perform the multiple downshifts may create the perception of "throttle delay". In reality, it is a design characteristic and normal behavior for the M DCT transmission when operated in D or S mode, rather then a malfunction or deficiency.
[NEW] Due to the ongoing quality optimization process, the newest version of the M DCT software provides additional improvements to the transmission drivability, resulting in further reduction of shifting time and engine torque application.
[NEW] To significantly improve the throttle response (or to reduce "throttle lag"), reprogram the vehicle with the current ISTA/P version (target integration E089-09-03-510 or higher, introduced in ISTA/P
2.33.1).
[NEW] In order to completely eliminate the delay sensation, as described above, the customer needs to operate the M DCT in the manual mode (paddle or gear lever manual shifting).
Explain the M DCT's operating behavior, as described above, to the customer.
WARRANTY INFORMATION
Covered under the terms of the BMW New Vehicle Limited Warranty or the Certified Pre-Owned Program.
Disclaimer