Question
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Followup To
Question -
I have a 2002 530i with Premium and Sport packages and 71,000 miles on it. It has the STEPTRONIC automatic transmission. I have an issue with the car:
What would cause the car transmission to intermittently transfer in and out of the "sport" mode while in the gear selector is in the normal drive position? This phenomenon seems to be more frequent when the outside temperature is warm/hot - above 85 degrees. The dealer "reprogrammed" the transmission while under warranty, and I have had the transmission serviced (oil changed and filter/gasket replaced by a qualified independent BMW service shop at 60,000 miles). These intermittent transfers in and out of the "sport" mode occur at 75 mph going down the freeway and are not noticeable other than the dash board indication. The intermittent transfers also occur at 30-40 mph, and are noticeable since the car seems to try to "hunt" for the proper gear when maintaining that speed - shifts back and forth between second and third gear. The indication on the dash of a transfer into the "sport" mode also occurs when the car is in neutral when the car is stopped or when the car is in motion (i.e., coasting to a stop). Any help you can give would be appreciated.
Answer -
Thomas, the dash indicator goes from "D" to "SD" on it's own? It doesn't go to manual mode "M1,2,3,4,or 5"? This almost sounds like the shifter is sending an incorrect gear selector position to the trans. control module (EGS). How often does it do this? Does it do this everytime you drive? Once in a Blue Moon? If a dealer had your car how many times do you think they would have to drive it to get it to act up? How many miles?
-Evan
Evan,
The intermittent transfer from "D" to "S" occurs very frequently when the ambient temperature is above 85 degrees, and the car has warmed up. I would estimate that when the temperature is around 100 degrees, the transmission automatically transfers in and out of the "S" mode every few minutes. When the dash indicates that the transmission is in the "S" mode, it down shifts, and the engine revs higher. When the "S" indication reverts back to "D", the transmission shifts to the higher gear, and the engine drops in RPM. It never goes into the manual modes unless I select those gears with the shifter. I did take it to a dealer, but they were befuddled by the problem - could not reproduce the problem due to cool day/cool car. The transmission only does the intermittent transfer under light throttle, or with my foot completely off the gas pedal - regardless of speed. The car works normally when accelerating, or when I manually select the gear via the shifter. The car has 71,000 miles. Thanks again for the help.
AnswerThomas, I would take the car back to the dealer and speak to your service writer and tell him of the situation and speak to the shopforeman. Drive the car until the vehicle is exhibiting the shifting symptom and return to the dealer and get the shopforeman with the GT1(diagnosis machine) to drive with you. He will look at the statuses of the powertrain control modules to see if he can identify the faulty component or signal. He may have to drive another E39 to get a baseline to check your information against. As long as you are patient and pleasant to deal with they should be more than willing to do this for a small amount of labor.
-Evan
