993claus

Hi. My 1994, 993 c2 has no speedo signal. The speedometer has being checked, and it worked. The connection from Centra Informer box to speedo is ok.
BUt can someone tell me what pin the signal comes in to the Central Informer, and where the signal comes from?
I have never bin driving the car, and bought the car without the speedo working.
Sorry for my English 🙄

Thank you, Claus, Denmark

jay@EZimmoblock.com

For ABS cars:
ABS Control Unit pin 13 --> X1/1 -9 -->Central Informer I/10 (WH/RD wire)
For ABS/ABD cars:
ABS Control Unit pin 40 --> X1/1 -9 -->Central Informer I/10 (WH/RD wire)

993claus

Thanks. Now i tested connection, and it's ok. But still no speedo.
is it possible to get a diagram showing the pin numbers and what goes in and out of the ABS box?
Is it possible to get speedo signal by lifting and turning one of the wheels? Or must i drive the car?
I can see that someone has messed around with the wiring, so i think the problem can be anywhere...

Thank you in advance, Claus

jay@EZimmoblock.com

Claus-

Here are 2 schematic pages that will take you a little further. The first shows the wheel sensors and the second shows the output to the C.I. (M224 is ABD Option). Note that the ABS output sent to the C.I. is from the LEFT REAR wheel. You should be able to get a response by rotating the wheel by hand. It may be too slow to register on the speedo but you should see 8 pulses per wheel rotation at the C.I. output and speedo input. If you have a scope, probe around. The third page may be helpful. Note that the speedo gets power from Fuse 18. Have you checked that?

Greg Bell

Several years ago I had some body work done on the car and when I picked it up and drove away the speedo wasn't registering. The owner of the shop where the work was done took the car with me, to a Porsche independent specialist to have a look at the problem. A mechanic walked over to my car and replaced one of the fuses, problem solved.

I don't remember the number of the fuse and looking under the fuse box lid I see no mention of the speedo. Can someone with more electrical knowledge of our cars please let us know the fuse number to check?

993claus

Perfect 🙂👍. I have a occilloscope, and think this will help me a lot. Can't wait to come home from work and get to the car 😊😊

jay@EZimmoblock.com

The tach is powered from the same fuse. Does it work?

993claus

Hi guys. It looks like i have signal in to ABS box, but nothing out. I have 12v on the box. Fuse is ok, and my tack works.

​​​​​It would be nice if i could try one other box to be Shure. Do you know what a used box will cost? Are there other things I can test before I buy a box?
by the way, ABS don't work when I brake hard..

Thank you all🙂🙂

jay@EZimmoblock.com

Are any of your dash warning lights on?
Confirm 12v on ABS connector pin 24.
Do you have access to a Porsche diagnostic tester?

993claus

Is it possible to get a pin layout on the ABS control connector?
i have no access to Porsche tester😔

993claus

And no light are on when started 🙂

jay@EZimmoblock.com

Here you go.

993claus

Hi again 🙂

Just see there are no 12v on pin 24.
What is "terminal 61"?

993claus

Sorry, with box connected, 12v is ok