Mechanics

ABS LIGHT AND ENGINE SHIFTING ISSUES

1994 GMC Van

Brakes problem
1994 GMC Van V8 Two Wheel Drive Automatic 63000 miles

Good evening!

I have a GMC vandura conversion van. Just after we purchased the van the ABS light in the dash, flashed on and the engine seemed to " pull down" it was pretty quick and I almost thought it didn't really happen.

Well recently while driving home I came to a stop light and slowed to a stop, upon accelerating the dash light once again came on and the engine did in fact pull down, my speedometer wouldn't register over 5 miles per hours. It wasn't as if it slipped out of gear more like a slowing down and creeping along. I pulled over, turned it off, waited a bit, started it up and was able to drive a bit further down the road without issue.

We stopped at a gas station, upon leaving the station the light came on again. I was able to drive but this time it would only get up to about 30 miles per hour, it felt like it wouldn’t shift. So once again we crept along.

We pulled off. My husband unplugged the ABS fuse, everything started fine and we were able to drive home without further issue.

We took the van to a mechanic who said we needed a several transmission parts replaced or a whole new transmission. We were told that the ABS codes were probably just a coincidence. I am not a mechanic but I don't think it's the transmission but that it is related to the ABS light.

We pulled the codes off of the ABS and they were " rear wheel sensor (signal?) Faulty" and " Rear wheel sensor (signal?) Missing". The Check engine light also came on and it referenced the EGR valve.

Should we replace the sensors on both rear wheels? Do you think it is transmission issues (we replaced the trans filter and fluid, it was red, a bit dark but didn't smell burned nor was it brown). Is the EGR valve involved in the above issue?
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Pricefamily
September 7, 2010.



Get another opinion for sure as

If it was a tranny issue disconnecting the ABS shouldn't effect on the way truck drive

if have speed sensors codes that should be replaced and or checked 1st

EGR codes also may effect engine as it may stall when it comes to a stop or emission with high NOX

what do you have for codes

BMRFIXIT
Sep 8, 2010.
I believe the codes were 24 when terminals A and B were jumped and 36 and 27 when terminals A and H were jumped.

Tiny
Pricefamily
Sep 8, 2010.
None of the codes indicate to any transmission problems all points to a speed sensors
check ABS wiring at each tire and suspect sensor if wiring OK
DTC 24 speed sensor
DTC 36 - MISSING VEHICLE SPEED SENSOR SIGNAL

DTC 27 - ERRATIC LEFT FRONT SPEED SENSOR

BMRFIXIT
Sep 9, 2010.
I will do that! Or rather my husabnd will! I did mistype the code 27 should have been 37. With the codes pertaining to the rear sensors should we check and or replace both? Would eitehr cause the engine to act the way it did?

The mechanic did say it was pulling up a code for transmission fluid hot so we replaced the filter and fluid and it hasn't popped up another trnas code.

Could a flaw in the ABS system make the vehicle act as described?

Thank you

Tiny
Pricefamily
Sep 9, 2010.
Speed sensor will effect ABS, transmission and engine
some have one sensor at rear and some have two rear sensor check by the rear tires if have wires
if not check at rear differential or at rear tail end of the tranny

BMRFIXIT
Sep 9, 2010.