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Porsche 944 Keyless Entry Issue w/ Factory Alarm

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=4300
Printed Date: July 30, 2025 at 1:01 AM


Topic: Porsche 944 Keyless Entry Issue w/ Factory Alarm

Posted By: tkt2rde
Subject: Porsche 944 Keyless Entry Issue w/ Factory Alarm
Date Posted: October 09, 2002 at 9:23 AM

I apologize in advance for the long thread.

Anyone have experience with the Factory Alarm system on a 89 Porsche 944 Turbo?  I just installed a keyless entry unit (AutoPage RF-1055KE) on mine and I am having an issue that I am not sure how to remedy.

The factory locks work like this:

... insert key into door handle and turn clockwise and counterclockwise to lock and unlock both driver and passenger door...  lock-knobs on top of the doors will go up or down and when armed, LED's top mounted in the knobs flash.  The tumbler is strictly for electronic switch and does not control any mechanical feature for lock or unlock (I am not sure, but it may have a low voltage sensing switch that will unlock the doors automatically in the event of battery drain).  Also, this system works by using the key in either driver or passenger door.  There is a button switch in the center console that will lock/unlock the doors, but there is a catch...  it will lock the doors with the ignition off, but will not unlock them.  With the ignition on it will do both.  There is also a tumbler for the hatch in the rear which is also strictly electronic, and it locks/unlocks the hatch only.  The hatch may also be unlocked from a button on the drivers kickpanel.  When you shut the hatch, it is mechanically locked.

The factory alarm:

The alarm is armed when you lock the door and monitors a hatch pin, hood pin, door pins, and I was recently told... the radio.  (Which I have replaced, but never had any alarm issues until after installing the keyless entry... so I don't think this is the gremlin)  Another feature that may be important is that when the alarm goes off, the locking stage is activated... so if you arm it with the windows down and someone attempts to pull up the lock knob, the knobs are instantly pulled back down as the horn sounds.

Installing AutoPage Keyless Entry:

12volt power to constant 12v in headlight switch harness.

Ground directly to chassis.

Horn Output to Relay that applies 12v directly to horn.

Starter Interrupt not connected. (factory alarm kills starter)

2 step unlock output not connected.

2nd Channel output to Relay that applies trigger to kick panel hatch switch.

Domelight output directly to domelight.

·          The door trigger switch I found was daisy chained from the driver switch to the domelight, then to the passenger switch and finally to the alarm system.  I wanted to make use of the illuminated interior delay-off feature after locking, but the way it was wired in… I had to take the domelight out of the chain and use it only with the Autopage… the door triggers no longer control the dome light, they only trigger the alarm… I found this out by my first attempt to wire it directly to the back of the driver door trigger and because the alarm is armed with the locking, it thought the door was open and sounded the alarm because the Autopage was still applying the switch for the illumination delay.

 

Switched Ignition output to switched 12v in headlight switch harness.

Parking light output directly to left and right parking light wires in headlight switch harness.

Door Unlock(-)/Lock(+) output to BROWN / Red Stripe wire in drivers door harness that tested 12v constant at rest then ground during unlock.

Door Lock(-)/Unlock(+) output to BROWN / White Stripe wire in drivers door harness that tested 12v constant at rest then ground during lock.

Finally, the problem:

Programming via valet switch with ignition on/off feature works fine.

Pressing the hatch button on the remote, unlocks the hatch fine.

Pressing the lock button on the remote, locks the doors, flashes the parking lights and dome light once, and blips the horn once, great.

Pressing the unlock button on the remote, unlocks the doors, flashes the parking lights and dome light twice, (dome light remains illuminated for 30 seconds) and blips the horn twice, great.

Screwy Thing #1:

If I unlock the car, get something out, shut the door… forgot something, immediately open the door back up… nothing.   Shut the door go into the house for a few minutes come back out, open the door… alarm goes off.  Click unlock on the remote… alarm shuts off.  I thought it was passive arming by the AutoPage, but I made sure active arming was programmed and the doors never locked.  The factory alarm never had passive arming.  Confused.

Screwy Thing #2:

I unlock the car, get in, start the car and go into town… get to destination, park the car, shut it off, open the door… alarm goes off!  Click unlock on the remote… alarm shuts off.  If I click unlock on the remote before getting out… alarm does not go off. 

The Autopage has ignition controlled lock/unlock feature which I turned on after this started thinking it was as good as clicking unlock on the remote when I shut the car off.  Well, it worked and the alarm does not go off when I get out.  But if I leave it unlocked and pump gas… go to get back into the car… alarm goes off… didn’t fix that part of the problem.  Also, say I am on my way out of the driveway and forgot my wallet, put the car in neutral… can’t open the door because it is locked… no problem, click the central unlock button on the console (works because ignition is on), doors unlock, open door… alarm goes off.  I have to shut the car off, then click unlock on the remote to shut the alarm off.

Before you could get into the car, start it up, then click the central locks to lock the door.  Leave it running, click central lock to unlock get out… alarm would not go off.

I figure it has to do something with the factory alarms arm/disarm sequence getting off somehow and it probably is related to the center console switch and its ignition control… but I am not sure how to remedy.

If you hung on this far… thanks for reading this long post.  Any ideas?




Replies:

Posted By: Velocity Motors
Date Posted: October 09, 2002 at 10:02 AM

Screwy Thing #1: Some systems still require a window of about 10 to 20 seconds after active arming for the system to engage. Other require 0 time but the system you have may have a delay for the active arming.

Screwy Thing #2: Very interesting problem. Did you make sure that the ignition wire is in fact receiving and cutting out the ignition power with the key ?



-------------
Jeff
Velocity Custom Home Theater
Mobile Audio/Video Specialist
Morden, Manitoba CANADA





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