Volvo 850 Made from 1993 to 1997, this Volvo line was available in both a wagon and a sedan, both with were graced with several trim levels.

No Speed Signal To My OBD-II Port

Old Jul 26, 2012 | 01:27 PM
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Default No Speed Signal To My OBD-II Port

I have a ScanGauge and a few weeks ago I plugged it in and quickly learned that it is no longer showing me real time MPG, AVG MPG, SPEED and it does NOT reset after the car has sat for several minutes. About the same time I realized that my cruies no longer works. The strange thing is that my speedo works.

So, if anyone has insight on this I would appreciate the help. Where does the cluster get it's speed signal from and where does the OBD-II port get it's live data speed signal from?

No, I do not have any error codes in the OBD-II port and I do NOT have an ABS light on in the dash (the bulb does work).
 
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Old Jul 26, 2012 | 08:18 PM
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I just learned that I don't have a ABS module. My car has a computer that looks like a ECU.
 
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Old Jul 29, 2012 | 09:26 PM
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Ok, I looked at the TS sheet for the cruise and at this point is said check several A7 ports for codes. So I left the car running and jumpped the OBD-I port and got the following codes:

B2 = 1-2-2

A7 = 1-2-2, 1-1-3, 1-2-1, 1-3-2

A3 = 4-4-4, 2-1-3, 2-1-4, 1-4-1

A1 = 1-1-1

A2 = 4-4-3, 4-3-5

A6 = It just flickered a lot and gave no codes. So I held it down for several seconds to clear codes and it stopped.

After I got all of the codes I cleared them. There was no CEL on in the dash before I checked for codes and when I scanned with my ScanGauge there was no codes and no pending codes.

Now, after I cleared the codes and got back in the car I had an ABS light, but still no CEL or CODES in the OBD-II port. So I drove the car around and the ABS light stayed on. Then I turned the car off and back on and the ABS light was out. So I drove around again and the ABS light stayed off.
 

Last edited by rspi; Jul 29, 2012 at 09:26 PM. Reason: alignment
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Old Jul 31, 2012 | 01:56 PM
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Have not taken the time to check codes in the manual, but I did do another cruise control test that checks the cruise control unit (relay under the fuse panel) for a speed signal paulse. It failed. The test says to lift the front end, turn the car on, put the volt meter on pin 8S and ground, spin the front wheels and see if the volt meter gives a 12 volt paulse. It is suppose to fluxuate from 0v - 12v. Mine did not fluxuate so it says to check the wire from the cluster to the relay unit.

There is a chance that the cruise unit gets it's speed signal from the cluster. Then there is a wire that goes to the ECU so maybe that signal is then sent to ECU after it goes to the cruise unit. I'll test that wire in a few days.
 
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Old Sep 15, 2012 | 09:06 AM
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Ok, fixed this a few weeks ago and forgot to update this thread.

One of the kind people on this forum was doing his ODO repair so he took the car for a spin with the cluster removed/unplugged and sure enough, the cruise did not work. The cruise gets it's speed signal from the cluster. The transmission sends a signal to the cluster, the cluster converts the signal and send the speed info to the cruise and OBD-II port (maybe ECU).

So, I pulled the dash pad and found a bad wire splice going from my harness to the cruise control (relay) or where ever it goes.
 
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