dpoul34

I followed the following Rennlist thread to test the speed sensors. All sensors tested fine.

https://rennlist.com/forums/924-931-...-resolved.html

I'm curious where to go next to get rid of those rotten ____!_____ and Antilock lights on my dash.

Also where is the ABS relay in the fusebox? Can't find a diagram for that to save my life.

gregeast

Same here. No ABS light at start up and no light for a minute or two after the car starts to roll. Light comes on after that. Checked the sensor resistance as per the thread above and everything checked out.

Help us ABS-Kenobi, you're our only hope!

dpoul34

One of my responses from an ABS-Kenobi told me that the ABS issue is a "black box" type of issue, that normally can only be tested with a Bosch Hammer tool to diagnose the code available at the dealer and then we can fix whatever they tell is wrong.

I hate to think I am handcuffed on this, but I have worked so hard on this car this winter to restore it and I NEED this light to friggin' shut off!

gregeast

According to my local Porsche mechanic, who was recently doing some work related to my wreck, there are no codes that can be pulled from this generation of ABS. Can't confirm that myself, just passing along what he said...

dpoul34

Then where do we go next? I couldn't even find an ABS relay in my fuse box!

gregeast

ABS Relay is in position G20. Silver one, third one in from top right. They're not cheap, $128 from Pelican, so it's not something I want to throw parts at. Maybe I'll try and borrow a known good one from someone local and see if that's it.

Bri Bro

Page 45-02 of the manual (vol III) has the ABS braking system. The relay in the fuse box is G20 on a 944. THe ABS diagram is on page 45-04 with all the parts IDed. The control unit and the hydraulic unit are " Impermissible to repair or dissemble". There is a book on checking the ABS, it is called the "TEST PLAN ABS" and the cover is shown on page 45-05 of the manual (vol III). Anyone got a copy or know where to get a copy?

Happy hunting.

Bri Bro

Here is a thread about the ABS TEST manual
https://rennlist.com/forums/924-931-...BS+TEST+manual

Also, the manual cover 928 and 944 so the 928 guys may have it.

Jet-Tech

The ABS section of the 944 maintenance manual can be found here;

http://www.cannell.co.uk/944_worksho...l3-chassis.pdf

For the wire diagrams you can also find them at the same site;

http://www.cannell.co.uk/944_worksho...electrical.pdf for years up to 87 and;

http://www.cannell.co.uk/944_worksho...electrical.pdf for 87 and up.

ZW 944

If you think that the relay might be bad, but don't want to spend the money on a new one since it may not be the problem anyway, there is a way to test the relay.

What I did was pry the metal cover off the relay, and re-install it. When you turn the car on, there is a metal arm inside the relay that should move. if it doesn't your relay is probably bad. to test further, use something like a pencil to flip the metal switch arm manually. this should turn the light on the dash off. if it does, then the relay is your problem.

I had the same problem with my 87 NA, and after cleaning all the sensors, it turned out to be the relay after all.

dpoul34

I do not have a relay in G20 nor do I have any open place to put a relay in G20. It's just a blank cap in that position.

http://i228.photobucket.com/albums/e...4/100_0095.jpg

(sorry, picture kept failing when I tried to load it here)

Yarf

What year and model is your car.

dpoul34

1987 944 NA with 111,000 miles.

Yarf

I have a 1987 NA without ABS, therefore G20 is not installed. On the inside of the fuse panel cover there is a layout and description of the fuses and relays.

dpoul34

And I can completely accept that. If I don't have ABS, then why is the Antilock light on the dashboard on?