2002 Boxster window won’t lower/ engine won’t start

[booper222]

One day all is good. Next day no joy. Rainy day, I come home and try to open the passenger door. The window will not drop down. Neither internal or external handle will drop the window (in retrospect I smell something). The window button does work for few times and then stops. I can’t get the window to roll up. I tried to start the car with no luck. No check lights. I unlatch the top release and both windows roll down to the proper spot. I re-latch and they roll up. When I tried to lock the door with the fob it sometime failed. It would lock/unlock. Each time it beeped twice which means it senses the door is not latched even though it is closed (I did check all the other lids, door, and arm rest)

2002 Boxster. Next day all is good except the car won’t start. Windows roll down when either handles are lifted but car will not start. Then I noted smoke coming from the door. It was hard to tell were it came from. I pulled the battery ground. Pulled the door apart sniffing as I went. Harness looks OK. Exterior handle micro switch is good. Door latch motor and switches seems suspect. My schematics are for a 2001. In all the different modes only terminal 1&2 for the motor close show 5.6 ohms, and door control terminals 3 &4 are closed with the latch in the locked position. None of the other terminals change state when I change the latch set up. I’m assuming this unit is trashed?????? Help! But why. It doesn’t smell smoked so I figure there is another issue.

What is left is the window motor and wire harness…and why the car wont start. Help and ideas would be great

[Britwrench]

Check under the driver's (left) seat, the alarm control unit is under the seat and if there is any water there, the control unit will short out.

[booper222]

Thanks, Will do. Just reading about the immobilizer. There's a 15 amp fuse there too. The all latch contacts go directly to the alarm module. BTW, more info the engine cranks but won't start.

[booper222]

New development. After eyeballing everything, I hooked up all the fixtures other than the inner panel, speaker, and airbag. I powered up and watched for smoking. All was good. Windows worked, car started, windows dropped with handle lifted...no smoke. I started the jiggle and sniff test. Got to the door latch and as soon as I got near the wires everything went nuts. Thought I had bad harness but pulled the latch out and sat it in my lap. Found twisting the connector created all kinds of craziness. Pulling on the wires didn't create the issue. Checked the Female connector and was going to pull the pins but didn't have the right tools to re-seat them.

I'm going to order a new door latch. I'm open to any more ideas. I'm not sure I've found the issue...still don't see where the smoke came from. I did look at the window motor but didn't see any "smoking" gun there.

I also hope this helps others...

[booper222]

Found another possibility. Just finished reading "Strange Electrical Problem" post. Just what poster Brit said though the carpet is dry and the tray is dry under the driver seat...today

[Jeff396]

I hope you have the Durametric scan tool. Turning on the ignition without the air bag connected turns on the air bag light. The dealer charged me $50 to reset it. I won't make that mistake again!

Jeff

[booper222]

Yep, I got the error msg. Went through this when I replaced the Alternator and started the car up with the seat out. I wondered if I would create the code but figured it was worth it instead of sitting there with my face in front of the air bag while I did all the testing. Last time my local shop known for working on high end cars reset it for no charge and just asked that I remember them next time I needed some work...and yes, I went back to them for some basic work instead of doing it myself. I'll go to them to reset the code...hopefully they will and I am willing to pay if asked.

This brings up a question: How does the system test the air bag? Frequency? two wires in can't be volts with much amps... really low mAs? I don't know what it take to trigger a air bag. Didn't want to know with my face in front of it with the way the door was acting.

[booper222]

I even thought of putting in a jumper wire in the air bag connection or in the connection for the seat. I would imagine you would have to know the resistance so that it would feed back the correct value to the module...that or I will burn up something

[nosnow4pc]

Possibly the ignition switch, the electrical portion behind the mechanical key. I've heard that going out will cause all sorts of strange electrical issues including no-start.

Although not on this car a prior Porsche had a bad switch which cause random no start and problems with the exterior lights.

[booper222]

Thanks, Nosnow, I'll keep that one in mind. Ive heard of similar issues

[booper222]

Ok, think I got it fixed. Lots learned. I’m going to pass it on what I think I found. The old latch had two cold solder connections. Of concern was terminal 8 – the common to ground. I only found this out after installing a new latch and took apart the old one. It took a while to find it and a powerful magnifying glass. Had to wiggle the plug until I could see the post wiggle above the solder joint.

My wiring connection drawing did not match what if found with the new latch. I’ll include that info. I simulated the conditions on the bench. Out of the box the winding showed 26.1 ohms, note change after I powered the unit the value dropped. My drawing shows terminal 9 used for close winding but nothing is wired to 9. My drawing shows two coils like a solenoid but a motor is used and is revisable.

Door closed & locked
1&2 – winding – 6 ohm
All contacts open

Door closed and unlocked
1&2 4 ohms
3&8 Closed

Door open and unlocked
8&4 closed
8&3 closed
1&2 4.5 ohms

9 not used, as per drawing 5&6 – key (passenger door with no key), 7 safe contact


I could not locate the source of the smoke unless it was intermittent connections or my eyes were messing with me. I did find the harness gang connection at the doorpost a bit loose. Lots learned. Hope this helps someone. The Tech Forum really helped. Local shop will reset my code no charge.

Why I couldn't start my car: I believe that when the door was unlocked the cold solder joint at terminal 8 (common) must have been open which would have looked like the door was locked. I tried to start the car the Immobilizer must have seen a conflict between the unlocked driver and locked passenger and prevented the car from starting. That's my theory...

[booper222]

The final outcome. Local shop charged me $20 to reset my air bag code. Gladly paid. All appears to be working well. I soldered up and tested the old latch as a possible spare.