ABS/PARKING Brake Light

On Fri, 07 Oct 2005 20:25:03 -0400, "DANDT" <dwapperson.RemoveThis@hotmail.com>
wrote:

>I have a 1999 Dodge Ram 4WD 1500. The ABS and Brake light on the dash will
>not go out. There doesn't appear to be anything wrong with the brakes. I
>have checked the front and rear brakes and both are good. The brake fluid
>is full. I do not see any leaks. Why would both lights remain on? I even
>checked the switch under the parking brake to ensure it was not stuck. Any
>suggestions?

Take it for a ride and watch the speedo at low speeds. If it doesn't
show anything till you get over 15-20 mph, then what Joe said - the
speed sensor on the rear differential is gone. Cost me about $41 and
15 minutes to change one a few weeks ago.

Greg
 >> Stay informed about: ABS/PARKING Brake Light 

The ABS and Parking brake lights come on when you start the truck and never
go off. Replaced the speed sensor and that did nothing. The lights are
still on and the Brakes are fine. Any other suggestions?
 >> Stay informed about: ABS/PARKING Brake Light 

> The ABS and Parking brake lights come on when you start the truck and
> never
> go off. Replaced the speed sensor and that did nothing. The lights are
> still on and the Brakes are fine. Any other suggestions?

If the lights never go out, that indicates a more serious problem - the ABS
computer failed one (or more) of it's self-tests. Could be air in the
lines - low fluid level - or an electronics problem somewhere. Other than
the low fluid level (which I really doubt is the issue here), there's not
much you can do yourself. You need someone with the proper electronic
diagnostic equipment to look at it. Unfortunately, that usually means a
trip to the dealership, as few independent shops have any equipment to talk
to the Chrysler ABS system.
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> You didn't mention if it had rear or 4 wheel ABS. If you have 4 wheel ABS
> it could still be a failed sensor on one of the front wheels causing the
> ABS

A bad speed sensor doesn't cause the lights to come on until there's
movement.
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I didn't mention but it only has the rear wheel ABS. I replaced the speed
sensor today and nothing changed. I also noticed today that my speedometer
doesn't move until I reach about twenty miles an hour and it seems OK after
that. I also drops back to zero upon deceleration around twenty. Could this
be connected?
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Are you sure about that? There are 3 error codes that deal with the speed
sensor(s). Error code 6 deals with erratic readings while rolling and would
only trip the light when moving but error codes 9 and 10 deal with expected
resistance in the sensor wiring (including the sensor) and I would think
that they would trip the light regardless of motion.

--
If at first you don't succeed, you're not cut out for skydiving

"Tom Lawrence" <tNlOaSwPrAeMnMcIeN5G.TakeThisOut@earthlink.net> wrote in message
news:Lpf2f.12314$q1.7015@newsread3.news.atl.earthlink.net...
> > You didn't mention if it had rear or 4 wheel ABS. If you have 4 wheel
ABS
> > it could still be a failed sensor on one of the front wheels causing the
> > ABS
>
> A bad speed sensor doesn't cause the lights to come on until there's
> movement.
>
>
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Yep. Which speed sensor did you replace? IIRC, there is one at the
transmission and one on top of the rear, at least it is that way on the 97.
The RWAL uses the one on the rear axle.

--
If at first you don't succeed, you're not cut out for skydiving
"DANDT" <dwapperson.DeleteThis@hotmail.com> wrote in message
news:72ae96fd3930e920bc16bff3193d001c@localhost.talkaboutautos.com...
> I didn't mention but it only has the rear wheel ABS. I replaced the speed
> sensor today and nothing changed. I also noticed today that my speedometer
> doesn't move until I reach about twenty miles an hour and it seems OK
after
> that. I also drops back to zero upon deceleration around twenty. Could
this
> be connected?
>
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> Are you sure about that?

Pretty sure... a buddy and I spent the better part of the day
troubleshooting his ABS problem. He would get an ABS light shortly after
rolling. We disconnected each combination of two sensors (leaving only one
connected at a time), to try and use the speedometer to detect a bad sensor.
Each time, the ABS lights would go out after the self-test, but come back on
when he started rolling (because only one sensor was showing voltage
pulses). Now, it's possible that if a sensor failed in such a way as to
short closed, that would immediately trip the warning lights - I don't know,
we never shorted his connectors.
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> Yep. Which speed sensor did you replace? IIRC, there is one at the
> transmission and one on top of the rear, at least it is that way on the
> 97.
> The RWAL uses the one on the rear axle.

There's an output speed sensor on the transmission, but in '99, the
speedometer signal comes from the ABS computer (either 4W or RWAL systems),
which in turn comes from the RWSS. The transmission sensor wouldn't affect
the speedometer.
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I understand that Tom. I was wondering if he replaced the transmission
speed sensor instead of the one on the rear axle.

--
If at first you don't succeed, you're not cut out for skydiving
"Tom Lawrence" <tNlOaSwPrAeMnMcIeN5G.TakeThisOut@earthlink.net> wrote in message
news:1Ah2f.12368$q1.6546@newsread3.news.atl.earthlink.net...
> > Yep. Which speed sensor did you replace? IIRC, there is one at the
> > transmission and one on top of the rear, at least it is that way on the
> > 97.
> > The RWAL uses the one on the rear axle.
>
> There's an output speed sensor on the transmission, but in '99, the
> speedometer signal comes from the ABS computer (either 4W or RWAL
systems),
> which in turn comes from the RWSS. The transmission sensor wouldn't
affect
> the speedometer.
>
>
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I only replaced the one on the transmission not relizing that there was one
on the rear as well. I'm not sure how that comes out though. It doesn't
look like it screws in.
 >> Stay informed about: ABS/PARKING Brake Light 

there's a bolt holding the braket for the brake line that runs over the
sensor on top of the housing. take the nut off move the line's bracket out
of the way. and remove the rest of the bolt. the sensor simply slides out.


"DANDT" <dwapperson.RemoveThis@hotmail.com> wrote in message
news:aeca18cbf0b3d28275accb0d328e8d31@localhost.talkaboutautos.com...
> I only replaced the one on the transmission not relizing that there was
one
> on the rear as well. I'm not sure how that comes out though. It doesn't
> look like it screws in.
>
 >> Stay informed about: ABS/PARKING Brake Light 

That is the wrong one. The one on the rear controls both the speedometer
and supplies information to the ABS system. There is a single bolt and
bracket that holds it down. Remove the bracket and it pulls straight out.
Replace that sensor and your problems should disappear.

--
If at first you don't succeed, you're not cut out for skydiving

"DANDT" <dwapperson DeleteThis @hotmail.com> wrote in message
news:aeca18cbf0b3d28275accb0d328e8d31@localhost.talkaboutautos.com...
> I only replaced the one on the transmission not relizing that there was
one
> on the rear as well. I'm not sure how that comes out though. It doesn't
> look like it screws in.
>
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