1996 850 no speedo

Teddy1975 · Post by **Teddy1975** » 12 Mar 2016, 11:39

I've resoldered my ABS module and there are no ABS codes being thrown anymore.
But, I lost the speedo signal somehow, at first it was intermittent, now it's 99.9999% gone. Did a 120 mile drive the other day, and the odometer clocked 0.8 miles.

I have pulled the module and carefully checked my soldering again to make sure I didn't accidently make any shorts and all seems to be fine there.

There are no codes on neither ABS nor CI, which I thought there would be, if there is no signal detected from the ABS module?

Post by **Matty Moo** » 12 Mar 2016, 16:09

Is the abs light on or off?

ChronicKing · Post by **ChronicKing** » 12 Mar 2016, 20:01

I was having this same issue with my 98 s70 T5. The speedometer would randomly quit working and it ended up being the vehicle speed sensor. Found this out during my transmission replacement.

Teddy1975 · Post by **Teddy1975** » 13 Mar 2016, 01:36

Matty, the ABS light turns off after the first 2 seconds of self-testing.

CK: I thought of the VSS, but I thought it was too much of a coincidence with the resoldering of the ABS module.

Anyone know which pins in the ABS module harness are for the VSS? I don't want to just swap it without at least trying to figure out if the one I have is faulty. It's just about the only electrical problem I have left on this car

Post by **Matty Moo** » 13 Mar 2016, 08:18

The VSS on the trans doesn't feed into the module on your car. The abs module sends a speed signal based on what it reads from the wheel speed sensors to the cluster.

Something somewhere is wrong.

Teddy1975 · Post by **Teddy1975** » 13 Mar 2016, 09:47

Matty Moo wrote:Something somewhere is wrong.

I couldn't have said it more clearly myself

So it brings me back to that blasted ABS module. Am I right in that the vehicle speed is/should be reported to the cluster by pin 6 in the ABS module harness?

Post by **Ozark Lee** » 13 Mar 2016, 10:44

That is correct. It is a Yellow/Brown wire that terminates at pin A-3 on the instrument cluster. The only other connection point is at the junction blocks under the dash Block 24/13C pin 1.

If you can get an oscilloscope on it you should see a pulse train.

...Lee

Post by **abscate** » 13 Mar 2016, 12:28

Your ABS module is clearly fishy in Denmark..

Post by **Matty Moo** » 13 Mar 2016, 12:35

I tend not to ask people how their soldering skills are but based on what I see sent in to me 97% of the population can't do it. Not a knock on anybody, I can't finish drywall or hang a garage door correctly.

Teddy1975 · Post by **Teddy1975** » 13 Mar 2016, 13:22

I learned how to solder back in the late 80s by attending an after school class where we were first taught how to make an astabile multivibrator (basically just a flashing LED). After that I went to an engineering school, learning how to design and make PCBs etc.

All of that is 20+ years ago and I probably have forgotten at least 90% of everything I once knew, but the basic soldering/reflowing solder skills are not gone yet

However I lack some tools, especially the "helping hands" which I'll pick up tomorrow along with a better magnifying glass.