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Old 09-13-2012, 11:20 AM
bimmerfan52 bimmerfan52 is offline
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Location: Arizona
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Mein Auto: 545i
Originally Posted by kskane View Post
Thanks for the PDF, if I look at the diagram at the bottom, it indicates 4E87 is connected directly to Ignition Switch Interlock. So how do I test that part?
The normal sequence, as I understand it is this:

Car is in park and engine is off. There is no voltage to solenoid and it is in the extended locked position.

Engine is turned on and brake pedal is depressed. Voltage is then sent to locking solenoid which is energized and retracts the locking pin to allow gear shift lever to be moved.

When gear shift lever is returned to park (engine running) the voltage to the solenoid is interrupted and the solenoid spring returns it to the locked position and gear shift lever is locked again until brake pedal is again depressed.

Sequence of your car:

Apparently when you return the gear shift to park the solenoid is not releasing and returning to the lock position. Even after you turn the engine off, and the voltage should have been released the solenoid is still not returning to the lock position.

When you start the car the computer runs through a series of checks to see what micro switches are opened and closed and what modules successfully run their start up check lists. The physical position of the locking pin on the gear shift lever is signaling the ECM that it is not in its proper position, which generate the warning that the gear shift lever can be moved without depressing the brake.

You need to answer "Why isn't the solenoid returning to the lock position?"

I can think of only two possibilities:

1. The voltage is not being removed for some reason. I believe you could test this. Put the gear shift lever in park and turn off the car. Remove the negative battery cable which should remove all power from the car and discontinue any voltage that might still be applied to the solenoid. Reconnect the battery cable and start the car. If you don't get the warning then you have interrupted the voltage that continues to be applied to the solenoid and need to trouble shoot from there.

2. The solenoid is physically being prevented from returning to the lock position after the voltage is removed. I believe this is your problem. Is the spring broken? Is the solenoid locking pin not lining up with the locking hole? Is the solenoid sticky from a spilled drink? You might try to wiggle the gear shift lever once you return it to park to see if a misaligned pin "finds" the hole.

CTSC gave you the resistance of the solenoid. Did they give you the activation voltage that is sent to the solenoid? If you know this you can pull off the connector you circled in your picture and apply that voltage at will to the solenoid and see if it pulls out of the locked position and retracts when the voltage is removed.

After you run the check for the first possibility I think you will move to the second possibility and will probably need to dig deeper into the gear shift assembly to see the solenoid work and see why it is not physically releasing to the locked position.

Last edited by bimmerfan52; 09-13-2012 at 11:24 AM. Reason: typo
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