Won't start due to door sensor?

[kayw]

Yesterday I experienced a "non-start" problem.

Few week ago, I found the door sensor of driver side didn't work -- the internal light didn't turn on while driver side door opened. (passenger side's is ok)

Yesterday I cranked the engine, that engine would't start (starter works) A "dat" sound, 2-3 sound per second, came from passenger side, near glove box. (the "dat" sound is same as the sound when turn signal on)

I press the sensor (with my finger) of driver side door, "dat" sound is heard from glove box. No "dat" sound if I press passenger side door sensor", however.

After pressing on and off door sensor couple times, crank the engine, engine is fired.

Do I have to replace the door sensor, or do something to the alarm module??

My car is a right-driver-side. I couldn't locate the alarm module on the passenger side. I will do a try on driver side tomorrow.

Thanks,

Kay

[comicbook8@gmai]

unlikely that your door sensor is related to the no start ! the "dat " sound you are hearing is the relay probly for your internal light this is located under the hood passenger side just in front of windscreen black box . open this and get someone to press the door sw you will hear which relay is activating unplug it clean the contacts lightly with some fine sandpaper , it sounds like the dat sound is coming from inside the car because the back of the relay box opens out into the back of dash board . the alarm module is located behind a kick board on passenger foot -well , cigarette carton size box , but be carefull if you try the by pass procedure on clarkes the colors were not the same on my unit and i nearly set the car on fire when i tried it "nasty"

[earlr85944]

do you have the key switch near the door to disarm the alarm?
I think it is the larm module you are hearing, easier to find it when it is clicking.....
get that door contack working correctly, the alarm module is sensitive to the door open and closing sequence

[carsontc]

clean the door switch contacts

[kayw]

Hi all,

I clean the door sensor. The car starts as usual. There is no more "click" sound.

So, what is the relationship between alarm module and door sensor? As I know, if door is unlocked by pulling the knob, the fuel pump won't work. However, what is the "secret" of the door sensor?

Thanks for update and great help!

Kay

[nutzforporsche]

OK I'm now having this issue. I'm at the point of pulling out the Bushmaster and give it a dose.

Driving home the other day in fierce rain the damn alarm horn went off. I startled me when the horn went off. I was next to a semi when all this happened and I thought the horn was from the semi. Well..I drove in to work , parked the car and did the day. Came out after the end of the day and the damn thing wouldn't start and the horn from the alarm kept sporadically going off. Almost like a short somewhere. Well, 138.00 later the car is towed home. I get it home and once it is off the roll back it decides to start. I pull it in the garage, close the door and get in the house. The next thing I hear is the alarm going off again sporadically. Almost like something is giggling, as the horn goes off on and on. Finally it decided that is going to go full tilt boogie. From all the noise I decide to pull the battery cable and call it a evening. Well here it is Sunday. I head out to find the source. I check relays, Put the key in the alarm socket and turn it off and then back on . Hoping to find the problem by luck. Isn't that how you use commonsense on issues that just popup? If it all of a sudden starts it is something simple, was my early mechanical teaching.

I'm stumped! I do not know where to look. I did not pull the door sensors as I never set the alarm. Since I don't use this feature WTF over?

Anyone have any ideas?

[mr.944]

I have had this problem on my 90S2. I fought this no start problem for close to 3 years. It got steadily worse over time to the point I could not drive the car for fear of being left stranded. I took it to a mechanic which kept the car for over a month and replaced the crank sensor. I finally got to checking every thing and noticed that when the car didn't start, you could open and shut the passenger door and the car would start. Well we looked at the door jam switch on the passenger door and noticed that when the door was open the switch would stay pushed in. I pulled the cover off the alarm module to see that it is basically just 2 big relays. I would put the key in the ignition and the relay for the passenger door would click down and cut fuel and spark. I took a tiny piece of a credit card and wedged in between the contacts, the car has started every time since with no problems. I did change the door switch but left the piece of credit card in there just for cheap insurance. There is no documented way to bypass the later cars alarm modules with the 928 part number. So that is my way to bypass it and it worked fine.

[nutzforporsche]

I'm going to check this evening and see if this is it. The funny thing is this didn't start happening until after I took a few passengers for spins. Hummm?

Thank you for the help!!!!!

[kayw]

As I have solved the "door sensor-no start" issue of my car, just add some info:

I took off the carpet of the passenger side and locate a big black box (should be some kind of relay) , but there is no alarm module (the one seems as a cigarette box) Mine is a right driver side so I checkout the driver side (right) too but didn't locate alarm module too.

Second is, maybe you all know. The alarm system functioning as :

1) Lock the door by key.
2) Open the door by pulling the door knock
3) Crank the car... starter work (cranks) but the engine won't fire. (there is no power to fuel pump and spark)

In order to disable the cut-off, you have to lock the door with key. Wait for seconds, unlock by key again. I hear somebody say it should turn key-on-off 3 times too.

The above cut-off system happens on my car, at least.

[nutzforporsche]

Here is the update. I had a real sticky door handle and actuator. I took things apart and cleaned them with MEK (methyl ethyl ketone).
We call it methyl ethyl bad$hit. As this is the world best degreaser.

A good hint:
This stuff will take up spots off your drive-way like a champ. Pour a little on the spot and take a old cotton shirt and "dab" it briskly. The toughest grease spot will come up. Make sure you wear chemical gloves as this stuff will kill you, I'm not joking. Burn rags, DO NOT THROW in the trash. This stuff can last 20 years in the ground. Not good for the environment! You can get it at Lowes in a gallon can in the paint section.

Anyway back to the fun stuff.

It ate the old silly-cone and dirt off in less than a second. Stunk up the garage real good too! I hit it with new white lithium grease and now the passenger lock works like new. I pulled out the door sensor and took some emery cloth to it and cleaned up the contacts. It also is nice and smooth and clean.

I also took the passenger floorboard up to expose the DME and the alarm module. Not sure what I need to look for. Other than check to make sure it working like it is supposed to. I'll do that tomorrow after work as I'm wiped out tonight. I pray it is something simple.

[nutzforporsche]

After much check and testing. I now know what the problem was.

Drum roll please

The relay for the Alarm was hosed up!

I started putting the passenger door back together after a good cleaning and re-lubrication. The damn alarm horn started its stuff. The big frigging hammer on the bench was calling to me saying...GO AHEAD AND SHUT IT UP!!!.....DO IT !!!!!............DO IT !!!!!

Get off my shoulder devil!

I thought it was me moving wires around inside the door. I double checked all the stuff there and nothing. I decided to tap the alarm relay that is under the passenger floorboard. The alarm stopped for a moment. Then started up again, F'in piece of $H*T!!!!....
I then decided to pull the small two wire power portion off the relay. Not only did the car stop beeping at me...it started each and every time. HUMMMM

OH Yea Baby we are close, I can feel it.

I put it back on and the no start / horn problem came back. I took the black cover off the relay and it was a slight green mess at the bottom from corrosion. I cleaned it off, but it had no effect on subsequent tests. The first contactor inside the relay kept clicking like a madman, thus sending the alarm horn into a staccato from hell The big hammer was again beaconing me like a siren of the sea. Then out of nowhere, a small capacitor fell off on the bottom of the PC board.

In the IT business we call it TOAST.

So now I mush find another and have it shipped over night. I saw the one in the Bird parts section and just about laid my own egg!
Too rich for my blood! Sorry Wayne, nothing personal! I was cheap ba$tard with the 914 and this one is no exception