View Single Post
Old 09-24-2012, 08:27 AM   #1
Slow in, slower out
Join Date: Jan 1970
Location: Awesome, NJ
Posts: 4,646
My Ride: 325it
Touring rear window glass opening by itself, replacing glass release button

For reference:

The rear glass in my touring started opening itself a few weeks ago. At first, the glass would be unlatched and the interior lights would be on if I left the car unlocked. Then it started popping open as soon as I unlocked the car. A few days later, it started popping open immediately after I closed it or while driving.

Locking the car would prevent the glass from opening, probably because whatever module controls the solenoid prevents opening when the car is locked. This lead me to believe that the problem did not lie in any controller or module.

I opened up the little black plastic cover on the inside of the glass at the wiper and button. Unplugging the little 2 wire connector stopped the phantom opening but still allowed me to pop the glass via the key remote. I opened up the rest of the covers on the glass and found the ground for the button. With the connector unplugged, a volt meter gave me 5VDC at one of the two wires on the button connector (pin 3) and GND at the other (pin 1). Plugging the connector back in dropped pin 3 to GND and fired the solenoid. I assumed an internal short was pulling pin 3 to GND and pried off the cover on the button/handle to see what was going on inside. The inside of the button housing was wet along with the ribbon cable and its membrane switch section. I have to assume that water/dirt/corrosion contamination will pass enough current to falsely trigger the 5VDC logic level input.

I then tried to remove the offending switch assembly but met with 12 years of corrosion between the button assembly and the wiper pivot mounted on the inside of the glass. A careful combination of force and gentle persuasion allowed me to remove the button assembly in pieces leaving the wiper pivot and glass intact. I now understand why a lazy dealer tech will claim you need new glass just to fix this button. Look for photos later this week.

I just ordered some parts from Tischer based on this:
Hex nut, 07147172628
Hex nut, M8, 07119921104
Rear window key button with micro switch, 61319200673
Rear window key button gasket, 61318385694
WAVE WASHER, 07119904115 $0.09
Gasket, 61627197857

touring wagon rear glass hatch opens itself unlocked
Mod the driver. Participate in your local BMWCCA autocross or driving school. Have you joined BMWCCA yet?

Last edited by teamdfl; 09-24-2012 at 09:37 AM.
teamdfl is offline   Reply With Quote
Ads by Google

Guests, get your FREE membership to remove this ad.