Jump to content

The RennTech.org community is Member supported!  Please consider an ANNUAL donation to help keep this site operating.
Click here to Donate

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)


Contributing Members
  • Content Count

  • Joined

  • Last visited

Posts posted by aureliusmaxed

  1. now is the time to troubleshoot and isolate to the component level. id get a wiring diagram and check the path or signal from the dme to the cluster end connections. if you have a clear current path the next thing you would do is check with a durametric the live data stream of your rpm/speed and then you can see if the issue is just the cluster failure

    Sent from my iPhone using Tapatalk

  2. 1 hour ago, Loren said:
    It might be time to open the alarm module and see if it has water damage and/or corrosion. (IMHO)


    hi. the owner claims to me he bought a new unit which porsche dealer had programmed . i believe him but will open and inspect for obvious defects to the PCB

    bought a durametric to further diagnose any potential causes of failure

    Sent from my iPhone using Tapatalk


  3. hi all. a little update. since the central locking did not work i wanted to isolate a switch, path of current to the wires or eliminate a fault in the ACM.

    attached is a photo of the diagram with my comments that proved the wires and switch are good and i also tested the LED forward voltage. so the switch is good, but alarm module does not respond to the trigger signals. i jumpered pins 4, with 2 and 1 separate to test its function.

    what does this mean and can we confirm a faulty alarm module here ?? 2a885be9c7b52abe7c836d891f7aca32.jpg

    Sent from my iPhone using Tapatalk

  4. the P0600 was triggered with the ignition ON with ECM plug removed. just as I suspected, by reading up the code. now that i cleared it, its not coming back. thanks for the replies ! ill be looking into why the central locking system is not working. the key icon on a rocker switch in the centre console is doing nothing when i assume the doors should work.

    Sent from my iPhone using Tapatalk

  5. so i checked the four fuses good, and the orange power wire going to connector I pin 16 of the ACM and I get B+. there was one DTC and it was P0600 which I cleared and it didnt come back last on/off cycle with the ignition. it may have triggered as I disconnected either a DME connector or alarm connector while the ignition was on, perhaps.
    when i hit the lock button on the key making sure all the doors and hood closed i get one beep and two flashes on the key LED. i can open the driver door once its armed and the siren will go off. which means the alarm module not sending a signal to the lock solenoid. when i press the lock button twice i can then open the door without a siren, where after the alarm siren blips once.

    Sent from my iPhone using Tapatalk

  6. the website FAQ says limited to three cars managed by VIN and programmed into the adapter cable. what exactly does this mean ? that once i say for instance do repair work on three porsche's that's it, I can no longer do another one ? 

    or this means i can only work on three cars in one day ? very confused 

  7. Do you think it's worth it to close the drivers door and arm the system to check for the flashing of the alarm readiness lamps ? After ten seconds if all its inputs test good, the readiness lamp will flash rapidly. 

    If faults are found, the lamp will not flash during the check period of ten seconds. A fault condition is displayed by double flashing after the check has been terminated.


    However, I'm not sure if this would cause a no-crank condition, as the system is dis-armed when I'm working on it (I believe)

  8. Hi. Unfortunately I don't have a Porsche or access to a durametric scanner. :drive1:


    I do have a generic scanner, do you know how I can get it to work though ? I tried before and it seems like it can get connect but that's it. It won't work completely if you know what I'm saying. However it is claimed as compatible with porsche 996


    There's only one key, as far as I know.


    I read in the description of the Anti Drive off Feature

    "The anti-drive-off feature is activated when the alarm system is armed. If an alarm is triggered, terminal 15 for the DME control unit is interrupted and the ignition and injection systems are disabled."

    (obvious that DME pin is wrong though) 


    I havent checked those fuses you mentioned - it's a good suggestion but I am not sure how these would interact to trigger the computer's anti-drive-off function.

     Wouldn't the engine just crank and not run if these fuses were open ? I can check and get back to you tomorrow. And there is a fuse on the ACM and it's closed.


    I would like to tell the owner if he should tow the car back to porsche and have them re-program the system, or if it would be worth it to buy a duramatric scanner. He mentioned it would cost him over $1000 to have porsche do some service (although this could have been the cost for a technician to repair the wiring harness) 


    What's you opinion on the print-out sheet that I attached that come with the ACM ? Does it mean anything to you ? 

  9. LHD, Tiptronic, 1998 Carrera Coupe


    Hi all, new to the forum but I was consulting some existing threads in the public forums regarding similar and related issues before I started an attempt at this job. I have access to the full wiring diagrams for the vehicle, the pdf is "996 Wiring 1999-2000.pdf" and can be found on google. I had them printed out on large sheet paper so I could trace the wires and go through all the possible issues without having access to factory scanning tools. I'm an electronics and industrial instrumentation technician hoping to build more work experience and reputation in order to get access to more of these repair gigs in the future on higher model cars.


    I am working on a 1998 Carerra (Japan market) that was installed with a 'fancy' alarm system that sat on top of the existing setup and most of it was removed prior or at delivery, and I spent yesterday inspecting and repairing the wiring harness from the hack job that was previously in there. Today I went through the troubleshooting steps in order to eliminate probable causes of a no-crank.


    The current owner had ordered a new ACM (alarm control module) and had it re-programmed and had told me the porsche dealer said to him the reason it won't start is a 'wiring problem' which I believe I had repaired all the wiring so far in the vehicle. I still have the old ACM with the car, it's just un plugged in the front storage.  After doing my troubleshooting today, I believe it to be the DME but my lack of understanding how the modules interact I'm not sure if it defective or just needing to have some re-programming of some sort which may require a porsche scan tool.


    Here's a take-away from my notes today;


    Check for B+ signal from ignition start to pin 30 on START LOCK RELAY SUPPORT REAR when ignition key set to START. B+ present

    Jumper pins 30 and 87 to test the relay is working. Turn ignition to START and check for engine cranking. Engine cranks.

    Check for B+ from pin 86 to the relay coil. B+ present 

    Ground pin 85, and turn ignition to START. Engine cranks. Relay is working.

    Check for current path from pin 85 on the START LOCK RELAY SUPPORT REAR to the DME connector pin 66 ACTUATION START LOCK. YEL/VI/BR wire. There is a path. PIN 66 on the DME is not switching to ground, and this won't let the car crank and start.


    Check for path of ground from DME pin 68 START LOCK to the shifter PARK and NEUTRAL. It grounds in each position, open in any other.


    Check for B+ on pin 88 on the DME which is the DIAGNOSIS W LEAD, and the only wire from the alarm leading into the DME. From my understanding of the alarm system from reading the description of operation from my ALLDATA catalogue, there must be some sort of handshaking going on between the RFID in the key fob, the correct serial and cypher in the ACM and the DME in order for this pin 66 to ground to let the car start.

    Checks at 7.37V with the DME dis-connected, and 8.34V with the DME plug end connected. I also ohmed out this wire 0.2ohm to check for any unusual resistance because seeing that voltage struck me as unusual. Again, I'm not sure of how this system interacts but I can only assume it's correct as I also tried to measure this voltage with the spare ACM installed with the same reading.


    What I wanted to ask for;

    Is this a wiring problem, problem in the ACM or DME and what would have to be done to rectify it.


    Warm regards, Aurelius


    Attached are three helpful photos of the DME ACM and a sheet that I believe came with the new ACM




  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.