Door Microswitches

[Richard Hamilton]

View this tutorial

Door Microswitches

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It seems that there are more and more cases of these faults appearing, and as some of our cars are reaching 10-12 years old, it is hardly surprising. I've compiled this information from past personal experience on both of my 996s, reading about others on here and other forums, referring to the workshop manual and wiring diagrams, and applying some logic. Hopefully you might find it useful, and save some grief when troubleshooting. DOOR MICROSWITCHES There are seven microswitches in eac

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• Author
  Richard Hamilton
• Category
  Carrera (996) - Common Fixes and Repairs
• Submitted
  08/14/2010 12:05 PM
• Updated
  03/13/2017 05:25 AM

 

[Doohan]

Is there any simple way to fault test the microswitches in the car directly from the alarm system or using a jump wire?

I have a a single-beep of the alarm horn on locking since over a year, the Porsche dealer could not solve the problem after billing me 600,00 € for a new interior monitoring sensor, Oddment compartment microswitch, Front lid microswitch, a new Radio contact and the PST check.

As a result they told me that I should leave them the car at least two or three weeks because they have to take out the seats and other parts to solve the problem... I paid and drove back the car home.

Edited March 1, 2011 by Doohan

[Loren]

Is there any simple way to fault test the microswitches in the car directly from the alarm system or using a jump wire?

I have a a single-beep of the alarm horn on locking since over a year, the Porsche dealer could not solve the problem after billing me 600,00 € for a new interior monitoring sensor, Oddment compartment microswitch, Front lid microswitch, a new Radio contact and the PST check.

As a result they told me that I should leave them the car at least two or three weeks because they have to take out the seats and other parts to solve the problem... I paid and drove back the car home.

Yes but you will need either Durametric or a PST2 or a PIWIS tester.

[Doohan]

At the Porsche Official Dealer they could'nt find the problem using the Porsche diagnostic tool...

[Loren]

Try another dealer - I have done this myself.

[the daredevil]

I'm troubleshooting a microswitch issue over here (also replacing a broken window regulator while I'm at it).

When I open the doors (both passenger and driver) from the inside, the window moves down and stays down while the door is open. However, when I open the door from the outside handle, the window goes back up when the handle is released (the interior lights also don't stay on).

Using the Durametric software, I can see the circuit closing when I lift the handle which leads me to believe the handle microswitch is okay (leaving one of the lock microswitches as the culprit). However, wouldn't a faulting lock microswitch exhibit the same behaviour regardless of which handle is used to open the door?

Thanks!

Derek

[Richard Hamilton]

Sounds very odd. Do both doors exhibit the same behaviour?

[the daredevil]

Yes, they both exhibit the same behaviour.

[number9ine]

I'm troubleshooting a microswitch issue over here (also replacing a broken window regulator while I'm at it).

When I open the doors (both passenger and driver) from the inside, the window moves down and stays down while the door is open. However, when I open the door from the outside handle, the window goes back up when the handle is released (the interior lights also don't stay on).

Using the Durametric software, I can see the circuit closing when I lift the handle which leads me to believe the handle microswitch is okay (leaving one of the lock microswitches as the culprit). However, wouldn't a faulting lock microswitch exhibit the same behaviour regardless of which handle is used to open the door?

Thanks!

Derek

The symptoms definitely point to the "open/close" latch microswitch on both doors, odd that they would fail at the same time though. The switch can only be ordered as part of a new latch assembly unless you try to repair it as shown in the DIY. The R&R is fairly simple if you already have the door open to do the regulator. I believe the part number is 8N1-837-015-C-M100 for the driver door, not sure about the passenger.

My wife's Boxster is having the same problem intermittently, and when it happens a movement of the latch away from the cabin with my finger can make the switch trigger. You might try the same to verify. The interior lights stay off when it happens because the car is led to belive the doors are closed. Good luck!

Mark

Edited May 18, 2011 by number9ine

[Hurdigurdiman]

there are 7 microswitches in each door. 2 for the door handle alone. Check this link out http://www.renntech.org/forums/tutorials/article/217-door-microswitches/

[the daredevil]

I'm troubleshooting a microswitch issue over here (also replacing a broken window regulator while I'm at it).When I open the doors (both passenger and driver) from the inside, the window moves down and stays down while the door is open. However, when I open the door from the outside handle, the window goes back up when the handle is released (the interior lights also don't stay on).Using the Durametric software, I can see the circuit closing when I lift the handle which leads me to believe the handle microswitch is okay (leaving one of the lock microswitches as the culprit). However, wouldn't a faulting lock microswitch exhibit the same behaviour regardless of which handle is used to open the door?Thanks!Derek

Replacing both door lock mechanisms resolved the issues.

[Ganzdachhaus]

Anyone know if the 996 Door Lock Mechanism is interchangeable with the VW version? Part numbers is 3B1837016 on both, but different Revisions... Looking at one out of a VW & it looks identical to the one from my 996, right down to the same broken microswitch. If I can use one from a VW box, that will save a good 200€

[Richard Hamilton]

I hear that the Mk5 VW Golf door lock is the same: http://www.boxa.net/forum/index.php?showtopic=54611&p=710848

[MN_Moose]

I am fighting what I think is a microswitch problem, my 1999 996 Cab C4 closes the windows, raises the top and locks itself randomly when parked.  I have not been able to figure out what causes this.  The car locks and unlocks with the key just fine.  The windows also drop when the door is opened as they should.  However, at times, the central locking switch on the dash will not work.  Any help or advice would be greatly appreciated.

[Richard Hamilton]

I guess the problem could be with the microswitch which senses the key being turned to the lock position.  I believe the convertible top will go up and the car will lock if the key is held in this position.  It is odd that it happens randomly, and that the central locking button on the dash also won't work sometimes.  I would have thought that a problem with the alarm control unit would more likely cause faults like that.  Any dampness under the left hand seat (driver's side in the US)?  That's where the alarm unit is located.

[MN_Moose]

Yes, the control unit got wet a few years ago, but I dried it out and was able to clean it up.  It has been dry now for 3 years. The control unit has been working fine up to now.  Do you think a Porsche dealer or independent shop would be able to diagnosis this problem with more sophisticated software? 

[Richard Hamilton]

Yes, I think you would be best to get a diagnostic scan with a Porsche tester.  Any good independent will have the equipment. 

[SVATS]

I am having a similar issue but seems slightly different than others. Any advice would be greatly appreciated.

2003 996 Turbo X50

-Passenger window drops when both the inside and outside handle micro switches are activated, however the window is not dropping the full 10mm (causing a slight interference with the pillar).

-No honk when locking the car

-Double honk when unlocking

-Drivers side operates correctly (drops the full 10mm)

-I've pulled the passenger side inner/outer handle microswitches out and they have no apparent issues.

-I have Durametric, so if anyone has troubleshooting advice with this tool it would be appreciated.

[Ahsai]

35 minutes ago, SVATS said:

I am having a similar issue but seems slightly different than others. Any advice would be greatly appreciated.

2003 996 Turbo X50

-Passenger window drops when both the inside and outside handle micro switches are activated, however the window is not dropping the full 10mm (causing a slight interference with the pillar).

-No honk when locking the car

-Double honk when unlocking

-Drivers side operates correctly (drops the full 10mm)

-I've pulled the passenger side inner/outer handle microswitches out and they have no apparent issues.

-I have Durametric, so if anyone has troubleshooting advice with this tool it would be appreciated.

 

Have you tried resetting the passenger window (hold switch for a few seconds after window is fully closed. Hold switch for a few second after window is fully opened)? If so and the problem still persists, it sounds like the window regulator has extra slop.

[Richard Hamilton]

Just to eliminate the passenger door window regulator, lower the window 2 or 3 inches from the top.  Grab the window, and try to move it up and down.  If it moves 1/2 inch or so, the regulator cables have slack in them, hence why it doesn't drop properly.

 

A double honk means there is a fault in the alarm system.  Use the Durametric to clear the codes, then lock and unlock it, and read any fault codes which come back.  

[SVATS]

Cleared the alarm codes, and now the double honk is gone. All seems to be well from the alarm side.

Thanks for the suggestion about the regulator, I'll check that tonight.

[Arthur in Oz]

I have a weird problem with my passenger window. It only happens (intermittently) when we have had heavy rain. With the ignition on (even while I am driving) and windows up, the passenger window “chatters”: jumping up and down the 10mm “access drop”. Window switch doesn’t work, Interior lights won’t dim nor the doors lock (using the dashboard switch). To rectify it, I need to open the door (using the inside handle). This stops the window chatter. By dropping the window a bit (and closing the door), all functions are reinstated - including auto-lock and light dimming. I have changed the external door handle microswitch - but the problem persists. Where to now? Any advice will be greatly appreciated.

[DBJoe996]

I am guessing you need a new passenger door latch mechanism.  One of the many microswitches built into the door latch mechanism is faulty.  I had some trouble with my drivers side door latch mechanism (not unlocking, not opening, repeatedly had to lock/unlock, window not dropping).  I replaced the entire door latch mechanism and now everything works perfectly.

[SVATS]

On 5/29/2019 at 8:41 AM, SVATS said:

Cleared the alarm codes, and now the double honk is gone. All seems to be well from the alarm side.

Thanks for the suggestion about the regulator, I'll check that tonight.

 

On 5/28/2019 at 2:56 PM, Richard Hamilton said:

Just to eliminate the passenger door window regulator, lower the window 2 or 3 inches from the top.  Grab the window, and try to move it up and down.  If it moves 1/2 inch or so, the regulator cables have slack in them, hence why it doesn't drop properly.

 

A double honk means there is a fault in the alarm system.  Use the Durametric to clear the codes, then lock and unlock it, and read any fault codes which come back.  

Mine turned out to be looseness in the cables that lift/lower the window from the regulator.

The micro switches are all activating, and you can here the regulator activating, however it is not moving the cables enough to lift/lower the window. It seems that it is just moving enough to pick up the "slack" in the cables.
Looks like a whole new regulator/cable assembly is in my near future. I believe these come as an assembly. Does anyone have a suggested place to purchase that's more reasonable than the dealer?

Thanks for everyone's input.

[hankster66]

On 8/14/2010 at 2:39 PM, Richard Hamilton said:

View this tutorial

Door Microswitches

---

It seems that there are more and more cases of these faults appearing, and as some of our cars are reaching 10-12 years old, it is hardly surprising. I've compiled this information from past personal experience on both of my 996s, reading about others on here and other forums, referring to the workshop manual and wiring...

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• Author
  Richard Hamilton
• Category
  Carrera (996) - Common Fixes and Repairs
• Submitted
  08/14/2010 12:05 PM
• Updated
  03/13/2017 05:25 AM

 

Hi Richard,

 

I just found your tutorial on troubleshooting microswitches, which is excellent. I think I am dealing with number (6) in your list... the door locked microswitch. I want to make sure I'm dealing with the correct door and also not missing something else... here's the scenario:

- Car will not lock using keyfob; it attempts to lock, then unlocks and then double beep... no variation to this.

- This throws Fault 60 on durametric "Central locking limit position Lock not reached"

- When I use the emergency manual lock process from outside car, only the driver side locks; passenger remains unlocked.

- From inside the car, when using lock switch, left door locks, which requires a double pull on handle to open door; the passenger door never locks (or attempts to lock) and opens immediately on one pull of the handle.

- The windows open/close appropriately on latch pull/release inside and outside the car. The only nuance is that unlike the driver side, the door does not "spring" open freely on latch pull so window automatically goes back up when I release because it thinks the door is still closed; however, when door is open and handle released it operates properly and none of this seems to throw a fault code so just may be a mechanical thing in the door.

 

Based on the above, I think I'm dealing with having to replace passenger side lock assembly only; would you agree? Are there any updates to repair process or recommended replacement part?