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ABS, Differential, Speedometer not working

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Old 11-12-2012, 11:36 PM
  #76  
jeff spahn
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Originally Posted by Rob Edwards
Not under the driver's footrest. The ABS brain is above the footrest. Red arrow is pointing to the bail for the harness connector. Disconnect the battery before pulling teh connector or badness will ensue.

Should you ever need to remove the footrest, in the pic below, there's a machine screw under the black plastic cap obscured by the letter 'A' in the pic. Pop that off, remove the screw. Easy peasy.

I didn't pull the battery connection when unhooking the ABS box. I did have the ignition off though. Works fine. Sean told me this was how to do it.
Old 11-07-2014, 01:45 AM
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Mrmerlin
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working on a similar issue on Rogers GTS we will fix it
Old 11-07-2014, 02:33 AM
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Rob Edwards
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I'm still having intermittent issues with having no speedometer or ABS. The spousal unit bought me one of Theo's nifty UDT999s for my birthday. Haven't had time to play with it yet but am going to give it a try this weekend and see.

Old 11-07-2014, 07:25 AM
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based on testing and swapping some parts around we may have a broken wire near the LR sensor the Hammer we are using is indicating no LR sensor,

Colin has suggested that the wire break will be near the CV joint.
we ran out of daylight to test the wires.\

Might anyone have the pin outs for the ABS connector thats above the drivers footwell
it looks like wire 42 and 43 are the wires we need to verify
Old 11-07-2014, 10:32 AM
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worf928
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IMHO, we will being seeing more and more of these types of errors as time goes by and the pigtail harnesses between the wheel hubs and the body harness deteriorates. (That harness carries ABS, brake pad warning, and RDK (if equipped) signals to the body harness.)

A couple of weeks ago I had one where 90% of the covering was gone so I pulled it to wrap in self-fusing tape. It looks like there is a braided nylon thread - probably used to aid construction of the harness - that shrinks with age or heat or time. As it shrinks it destroys the outer covering and thus the individual wires and ultimately their plug connections are exposed to the elements.

I cut the thread at both ends, wrapped and re-installed the harness. This winter I'm going to cut that thread on every harness in my garage where it is exposing itself through the covering its killed.
Old 11-07-2014, 11:21 AM
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Rob Edwards
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Agreed on gamey harnesses becoming a hassle- I have a spare, but how in the hell am I gonna replace it?





Pinout at the dash connector:





Here's the pinout (sorta...)



And the pinout in tabular form:

Old 11-07-2014, 11:23 AM
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Rob, that's what I call the body harness. There are four 'pigtail' harnesses that connect to that one; one for each wheel.
Old 08-04-2015, 02:53 AM
  #83  
Rob Edwards
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Now I don't even remember how it came up today but I came across the fact that for 91-95 there's a relay (XIX, 964 618 221 00) that lies between pin 12 of the ABS/PSD brain and the digidash.

In '93, the speed signal into the ABS/PSD brain comes in over pins 44 and/or 45 from the left rear ABS sensor. Then Pin 12 out of the ABS/PSD brain into the CE panel on Q25, through pins R and T on relay XIX, then out of the CE panel at pin P15 on its way to pin 6 of plug 4 into the digidash.

So- how to test that relay, other than swapping in a known good one? Anyone ever had a dead speedometer on an airbag car that was cured by changing this relay?
Old 08-05-2015, 11:26 AM
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FLYVMO
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Originally Posted by Rob Edwards
Now I don't even remember how it came up today but I came across the fact that for 91-95 there's a relay (XIX, 964 618 221 00) that lies between pin 12 of the ABS/PSD brain and the digidash.

In '93, the speed signal into the ABS/PSD brain comes in over pins 44 and/or 45 from the left rear ABS sensor. Then Pin 12 out of the ABS/PSD brain into the CE panel on Q25, through pins R and T on relay XIX, then out of the CE panel at pin P15 on its way to pin 6 of plug 4 into the digidash.

So- how to test that relay, other than swapping in a known good one? Anyone ever had a dead speedometer on an airbag car that was cured by changing this relay?
Rob,

How about temporarily installing a Dakota Digital signal converter, tapping the signal where it connects to the speed relay and then send the output to the speedometer, basically bypassing the ABS speed-to-speedometer signal conversion relay? That will tell you if the relay is bad. Maybe not the most economic solution ($85) but that little unit is very handy for adjusting speedometer readings, specially if you have non-standard diameter wheels.

Since the signal at that point has already been processed by the ABS computer it won't interfere with the ABS system.

Link: http://www.dakotadigital.com/index.c...rod/prd126.htm

Cheers!
Carl



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