alarm red LED continuously ON
#1
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alarm red LED continuously ON
Hello all,
i've been trying to solve a bugging issue on my 96 4S for a while with no luck.
The alarm LED is continuously ON when one or both doors are open
it doesn't matter which one. The car also unlocks itself depending on days.
Once both doors sensors are pressed, the LED turns off
I have checked both door sensors(which are basically two grounds connected to the car body), checked shorts or cut wires through the door hinges wiring harnesses, swapped the alarm computer with another one, scanned and tested the alarm system with the PST2, checked both trunk / compartment sensors, checked the central locking switch, but have found nothing relevant so far.
All the alarm sensors responded well, but i had recurrent errors codes from non plausible sensors position during alarm activation, which explains why it sometimes unlocks itself
There must be a bad ground somewhere, but where?
If any of you had a similar experience or have a suggestion please let me know
Thanks
i've been trying to solve a bugging issue on my 96 4S for a while with no luck.
The alarm LED is continuously ON when one or both doors are open
it doesn't matter which one. The car also unlocks itself depending on days.
Once both doors sensors are pressed, the LED turns off
I have checked both door sensors(which are basically two grounds connected to the car body), checked shorts or cut wires through the door hinges wiring harnesses, swapped the alarm computer with another one, scanned and tested the alarm system with the PST2, checked both trunk / compartment sensors, checked the central locking switch, but have found nothing relevant so far.
All the alarm sensors responded well, but i had recurrent errors codes from non plausible sensors position during alarm activation, which explains why it sometimes unlocks itself
There must be a bad ground somewhere, but where?
If any of you had a similar experience or have a suggestion please let me know
Thanks
#2
Instructor
I have no idea what is causing your problem, but you might want to start by checking the main grounding strap between the negative terminal of the battery and the chassis. I believe the original braided cable from the factory can suffer from corrosion between the wire and the crimped terminal lugs. This can result in odd electrical issues. The new replacement part from Porsche is relatively inexpensive and has a sheathing on it to prevent any moisture ingress/corrosion issues.
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#3
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thanks for the suggestion but the terminals are clean and the battery new; it is definitely alarm related, there is short with a sensor or a wiring harness
#4
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The occasional unlocking is strange. Might trouble with the central lock switch cause this? I'll verify later but I believe the switch toggles a ground input to the control unit to lock/unlock.
Edit: Sorry, I missed that you checked the central lock switch.
Edit: Sorry, I missed that you checked the central lock switch.
Last edited by hoggel; 04-28-2016 at 10:16 PM.
#5
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#7
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The "non plausible sensors position during alarm activation" doesn't match any of the possible displays in the Diagnosis Manual. Could be, "Position of the drives unplausible"? Or [any of the sensors wrong] during activation?
The 'drives' refer to the door lock actuators and position switches in the door lock mechanism.
The 'drives' refer to the door lock actuators and position switches in the door lock mechanism.
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The "non plausible sensors position during alarm activation" doesn't match any of the possible displays in the Diagnosis Manual. Could be, "Position of the drives unplausible"? Or [any of the sensors wrong] during activation?
The 'drives' refer to the door lock actuators and position switches in the door lock mechanism.
The 'drives' refer to the door lock actuators and position switches in the door lock mechanism.
I will pull the error code / number tomorrow and see what it is in english
basically it says that doors or trunk sensors are in an odd position when activating / locking the car with the remote
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however, i remember that when the central locking switch is unplugged the alarm's LED lights are not affected and are still on
What could possibly cause the self unlocking is that if one door sends a open signal because of a short circuit or defective sensor; like when you are in the car with both doors locked and that you open your door from the inside with the door
handle??
#11
my PST2 is set in French; i just tried to translate it into something that make sense in english
I will pull the error code / number tomorrow and see what it is in english
basically it says that doors or trunk sensors are in an odd position when activating / locking the car with the remote
I will pull the error code / number tomorrow and see what it is in english
basically it says that doors or trunk sensors are in an odd position when activating / locking the car with the remote
However, if all else is right with the system, I would have thought an error of an out of position sensor would manifest itself as a double blinking led, for having failed the system self test. Perhaps the alarm ctrl module (ACM) is bad?
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This is telling me that one or several micro switches are out of position (need adjusting), or bad... doors, frunk, engine bay, glove box.
However, if all else is right with the system, I would have thought an error of an out of position sensor would manifest itself as a double blinking led, for having failed the system self test. Perhaps the alarm ctrl module (ACM) is bad?
However, if all else is right with the system, I would have thought an error of an out of position sensor would manifest itself as a double blinking led, for having failed the system self test. Perhaps the alarm ctrl module (ACM) is bad?
I already exchanged with one from a healthy car with no result. Furthermore, when the alarm module is unplugged, the red led is on as always.
Also, the self unlocking problem is intermittent. I usually had to lock it twice since it used to unlock itself the first time; last week was another story, the alarm was starting to scream 15 seconds after locking, then i unplugged the battery for a night, and now it seems to work kind of normally but still the red led on
I have tested the resistance through the front trunk lock power part and it seemed to work fine. I haven't tested the different sensors with the PST2, trunk, engine compartment, doors, lights, and everything seemed responsive and normal
After thinking a bit about it, one thing i haven't checked yet is if the doors can both lock and unlock normally when using the door lock mechanism and how the LED light behaves; maybe a 964 613 134 00 microswitch has gone bad