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Old 09-16-2012, 10:44 PM
bimmerfan52 bimmerfan52 is online now
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Location: Arizona
Join Date: Feb 2012
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Mein Auto: 545i
Originally Posted by kskane View Post
Thank you BimmerFan32 for such a descriptive suggestion, but I am confused why does this warning only comes in the cold start in the morning? Everything functions fine i.e. "Solenoid returns to the lock position" during the entire day time, but just not on the cold start. CTSC guys did not give me the solenoid but I know when everything is working there is a voltage of 12.something without break press and 0.01/2 with break being pressed. Is there any other diagnosis I do further?
Upon further investigation I have discovered that there are two locking systems on the gear shift lever for 2004-2007 E60s, and the solenoid operated lock is only operational when the engine is running.

The first is a cable linking the ignition lock to the gear shift lever. The key can only be removed when the gear shift lever is in park. Moving the gear shift lever to park also operates a cable connected to the mechatronics transmission to lock the transmission output shaft. Conversely, the gear shift lever can only be moved out of park if the key is inserted and turned to a least the first position.

A second locking system is employed when the car is started and the shift lever is in the P or N position. The transmission control module sends a voltage to the locking solenoid to move it to a locked position. When the brake is depressed the voltage returns to zero and the pin retracts.

Either the mechatronics unit is not sending the signal or the TCM is not forwarding the voltage.

If you don't see the voltage to the solenoid on cold start up, but do see it after having driven the car, turned it off and restart it then I would guess it is the solenoid in the mechatronics unit that sends the signal to the TCM to send voltage to the gear shift lever solenoid. The mechatronics solenoid may not be operating unless the transmission fluid is warm.

If you haven't done a drain and fill on the transmission that is what I would start with. If you do it twice (with maybe 100 miles of driving in between) you will have 85% fresh fluid after both drain and fills. Even though the system holds about 11 quarts when you drain the transmission sump you will only get about 6 quarts out as the rest is held in the torque converter.
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