Kuchar

My car is C2 964 of 1993

Here is my problem with ABS:

ABS is not working
The indicator lights up all the time - does not go out even for a moment
If it has anything to pads worn light is lit as well, but brake pads and cables are new
When connecting Durametric, unfortunately did not see ABS module and get the message module failed to initialised or something like that
Tester does not see Airbag - the same message
The motor in the pump works because i move it by connecting directly to the battery
Is there other way to reset the ABS faults than using Durametric?

Perhaps one day someone had a similar problem so please help, any advice is welcome.

Maciek

964russ

Mine was the relay.

Worth a try, only cheap.

Kuchar

Tkank you, 964russ
What symptoms were in your car?

Henry964

Hello Kuchar

My car is also a 1993 C2 I´ve just had my ABS fixed, the symptoms were lights and alarm (beeper sound) on, but only going relatively fast, not always

The mechanic took the controling unit of the ABS to a electronics repair shop and they found two diodes that weren´t working, they changed these diodes and the issue dissapeared.

Hope this helps...

Silvertarga

My ABS and brake pad was lit, turned out to be the leads from the connector block to the interior
of the car (both were on right side)

Reolaced the rear (not too difficult) and spliced the front, lights went out

Kuchar

Henry964
My ABS unit was controling in repair shop - is ok.

Maybe i should check two relays located at the pump, but how. To which pin to connect the cables (+,-) to see if they work?

boxsey911

Russ had the dash lights and warning buzzer. He changed the silver relay in the main fuse box for one that was known to work and all was good. I was there at the time.

I wasn't so lucky. I had no lights or buzzer but the brakes kept locking up. The ABS clearly wasn't working. I needed a replacement ABS pump unit to fix it.

Kuchar

Thank You boxsey911 - my buzzer is already disconected ... You know why

Some new info:
All three relays (silver, and two black from pump) works perfect. I have pluged +/- to 85 and 86 pin, and heard click! In silver where other signal pins ...
Now i hace to check resistance between pins in pump conector - 12 pin plug.
Adrians book says (before i found rennlist forum it was my bible ) measure resistance across:
ABS solenoid valve FL - resistance across pins 1 and 2 - i could be wrong but i think there is misteake should be 1 and 4
ABS solenoid valve FR - pins 3 and 4
ABS solenoid valve rear - pins 5 and 4
Resistance shoud be 0.7 - 1.7 ohm

I will check in a few minutes.

Kuchar

Multimeter set to 200 ohm and:
Resistance across pin 1 and 4 - 1.8 - 1.9
Resistance across pin 3 and 4 - 1.9
Resistance across pin 5 and 4 - 1.8 - 1.9

What does it mean?
Maybe somebody who has perfectly working ABS could check resistance in his 964? Please ... please

Kuchar

Well
Subsequent steps leading to the knowledge of causes of failure ABS in my 964
I checked the solenoids and all three are working properly.
I gave them the power and found that they works
Today I was at the Porsche Center, my car was diagnosed using their computer ... and what ... and proved that my car has ABS and Airbag ... hahahahaha!
Their computer can not connect to the module ...
So, the problem is somewhere in the electrical system, most likely.
I wonder what now.
I check the pins in the central informer may be tarnished or dirty, and there is no proper contact ... who knows?
Can someone realizes that it can affect the ABS and AirBag not working and diagnostics computers cand find them in system? So dirty pins on the module central informer, can be the cause?

Please help

Kuchar

Pins and plugs cleaned - ABS still failed no good.

C24FUN

I had some similar problems with my ABS. The solution is described in thread entry #10 here:

https://rennlist.com/forums/showthre...eferrerid=4063

Good luck!

Jim G.

Kuchar

Jim!!!!!

After reading your post, I went to the garage to check the cable.
The two red cables have one battery connector and it was clean.
However, the wires were dull green. I cut two inches of insulation, and it turned out that all wires are GREEN!
Probably the cable too does not conduct electricity well, right?
So now I have a plan for tomorrow ... replace this two cables ...

Kuchar

Thank You, Jim!

C24FUN

I was amazed when I discovered how this simple issue could disable the ABS. Since re-terminating the cables and cleaning the contacts I have had no further problems. Hope it's a simple solution for your problems too!

Cheers!

Jim