Jeep Cherokee ABS problem

Good morning

I may have a problem with my ABS and I'd appreciate any suggestions. I
have a 2001 Jeep Cherokee Classic which I bought in August from a
garage which is not a specialist Jeep dealer. It has ABS, but while
driving after a recent heavy snowfall I got the impression that the ABS
wasn't working. I tested the brakes to check what the grip and handling
was like, and as I braked progressively, I got to a point where the
wheels started to lock and slide but I couldn't feel the vibration on
the brake pedal which you'd normally expect to feel as the ABS kicks
in. The braking performance was more like what you'd expect from a
vehicle with decent brakes and decent winter tires but no ABS.

I took it in to the (non-specialist) dealer today who tested the ABS,
said it was in perfect working order and charged me $35 for the advice.
They said there were "no codes" on the ABS, whatever that means, which
is presumably a Good Thing.

I can think of three possible explanations:

1. My jeep is in perfect working order and I'm a silly neurotic git.

2. The ABS is working but it's so poorly designed that it's barely
possible to tell the difference between ABS and no-ABS.

3. There is a subtle fault with the ABS which the non-specialist dealer
hasn't picked up. For example, is it possible that the ABS is in
working order but there is some fault with the sensor which tells the
ABS when to kick in?

I realise that the obvious solution is to take the vehicle to a
specialist Jeep dealer for a second opinion, but I'm in a remote part
of rural Newfoundland and I don't think there is one within two hours'
drive of here. So I'd appreciate any suggestions from this group.
Thanks.

Peter did pass the time by typing:

> I can think of three possible explanations:
>
> 1. My jeep is in perfect working order and I'm a silly neurotic git.



> 2. The ABS is working but it's so poorly designed that it's barely
> possible to tell the difference between ABS and no-ABS.

read on.

> 3. There is a subtle fault with the ABS which the non-specialist dealer
> hasn't picked up. For example, is it possible that the ABS is in
> working order but there is some fault with the sensor which tells the
> ABS when to kick in?

Slowly depressing the brake as you did will not trigger ABS. ABS on Jeeps
is for emergency stops when you apply the brakes quickly. The system they
use isn't like the luxury cars where ABS is part of a stability control
system.. BMW etc.

The easiest way to test ABS is find a dirt or gravel road, get up a
bit of speed (25mph or so) then stomp on the brakes, or on snow, try
stopping a bit faster.

Failing wheel sensors can cause this but generally one goes bad or
gets out of calibration before the other. That results in ABS kicking
in as you come to a normal stop.

The other problem Jeep ABS has is garbage/water intrusion at the ABS
computer connector. I have to remove/clean/reinstall mine about once
every year. Good contact cleaner and dielectric grease (sparkplug boot
grease) is all you need.

--
-- DougW -- 93 ZJ 4.0 http://members.cox.net/wilsond
HESCO Supercharger - 300W IASCA Stereo - Edelbrock IAS Shocks
Gibson Exhaust - rear DCpower - custom gauge install - Stillen Rotors
Banks Header - and BEER, in the fridge!

You need to take it out on a dirt or snow covered road and while going along
at a good rate of speed STOMP hard on the brakes.

You should feel the pulsations of the ABS cycling on and off through the
brake pedal.

By "progressively" applying the brakes you effectively prevented their
engagement.

Older drivers may know how to pump the brakes when stopping on slippery
pavement to avoid locking the wheels and causing a skid. But when it comes
to anti-lock brakes, the name of the game is "stomp and steer."


"Peter" > wrote in message
oups.com...
> Good morning
>
> I may have a problem with my ABS and I'd appreciate any suggestions. I
> have a 2001 Jeep Cherokee Classic which I bought in August from a
> garage which is not a specialist Jeep dealer. It has ABS, but while
> driving after a recent heavy snowfall I got the impression that the ABS
> wasn't working. I tested the brakes to check what the grip and handling
> was like, and as I braked progressively, I got to a point where the
> wheels started to lock and slide but I couldn't feel the vibration on
> the brake pedal which you'd normally expect to feel as the ABS kicks
> in. The braking performance was more like what you'd expect from a
> vehicle with decent brakes and decent winter tires but no ABS.
>
> I took it in to the (non-specialist) dealer today who tested the ABS,
> said it was in perfect working order and charged me $35 for the advice.
> They said there were "no codes" on the ABS, whatever that means, which
> is presumably a Good Thing.
>
> I can think of three possible explanations:
>
> 1. My jeep is in perfect working order and I'm a silly neurotic git.
>
> 2. The ABS is working but it's so poorly designed that it's barely
> possible to tell the difference between ABS and no-ABS.
>
> 3. There is a subtle fault with the ABS which the non-specialist dealer
> hasn't picked up. For example, is it possible that the ABS is in
> working order but there is some fault with the sensor which tells the
> ABS when to kick in?
>
> I realise that the obvious solution is to take the vehicle to a
> specialist Jeep dealer for a second opinion, but I'm in a remote part
> of rural Newfoundland and I don't think there is one within two hours'
> drive of here. So I'd appreciate any suggestions from this group.
> Thanks.
>

Hi Peter,
In order to prove your Antilock Brake System works you must choose
someplace where you will not hit anything like a large empty parking
lot. Then drive at the speed you would be traveling through that lot,
then pretend you're a complete idiot, and slam on the brakes hard like
in a panic, and don't release any as if you had a brain and wanted to
regain control, and working you should have no brakes, until well after
the object you pretend to keep from hitting. Like now you will have to
drive around it, as if you don't have brakes, because you don't!
God Bless America, Bill O|||||||O
http://www.billhughes.com/

Peter wrote:
>
> Good morning
>
> I may have a problem with my ABS and I'd appreciate any suggestions. I
> have a 2001 Jeep Cherokee Classic which I bought in August from a
> garage which is not a specialist Jeep dealer. It has ABS, but while
> driving after a recent heavy snowfall I got the impression that the ABS
> wasn't working. I tested the brakes to check what the grip and handling
> was like, and as I braked progressively, I got to a point where the
> wheels started to lock and slide but I couldn't feel the vibration on
> the brake pedal which you'd normally expect to feel as the ABS kicks
> in. The braking performance was more like what you'd expect from a
> vehicle with decent brakes and decent winter tires but no ABS.
>
> I took it in to the (non-specialist) dealer today who tested the ABS,
> said it was in perfect working order and charged me $35 for the advice.
> They said there were "no codes" on the ABS, whatever that means, which
> is presumably a Good Thing.
>
> I can think of three possible explanations:
>
> 1. My jeep is in perfect working order and I'm a silly neurotic git.
>
> 2. The ABS is working but it's so poorly designed that it's barely
> possible to tell the difference between ABS and no-ABS.
>
> 3. There is a subtle fault with the ABS which the non-specialist dealer
> hasn't picked up. For example, is it possible that the ABS is in
> working order but there is some fault with the sensor which tells the
> ABS when to kick in?
>
> I realise that the obvious solution is to take the vehicle to a
> specialist Jeep dealer for a second opinion, but I'm in a remote part
> of rural Newfoundland and I don't think there is one within two hours'
> drive of here. So I'd appreciate any suggestions from this group.
> Thanks.

Lee Ayrton did pass the time by typing:
> DougW wrote:
>
> [snip]
>> Failing wheel sensors can cause this but generally one goes bad or
>> gets out of calibration before the other. That results in ABS kicking
>> in as you come to a normal stop.
>
> Ahhh. Thanks for the clue. My `96 XJ's ABS kicks frequently (LF wheel,
> methinks) when braking over road divots, cracks in the road or the
> occasional tree shadow.

But before you replace sensors, clean the ABS computer connector.

--
DougW

DougW wrote:

[snip]
> Failing wheel sensors can cause this but generally one goes bad or
> gets out of calibration before the other. That results in ABS kicking
> in as you come to a normal stop.

Ahhh. Thanks for the clue. My `96 XJ's ABS kicks frequently (LF wheel,
methinks) when braking over road divots, cracks in the road or the
occasional tree shadow.

Thanks for those suggestions guys, I will try them

Good afternoon. I'm just posting a followup to our discussion about my
Jeep Cherokee ABS problem because I know you guys really, really care
about whether I got it to work or not.

Most of you suggested stomping hard instead of gently on the brakes.
After the next snowfall I tried this, but whether I stomped gently or
hard, it made no difference, there seemed to be no response of any kind
from the ABS. I then read the section about ABS in my glovebox owner's
guide (should have RTFM to begin with, I suppose) and it said that the
ABS light should come on for a couple of seconds when you turn on the
ignition. It isn't lighting up at switch on or at any other time,
suggesting there really is a fault and it isn't just my imagination.

I opened a box of electrics under the hood, looking for clues, and it
was full of relays and fuses. There was a diagram inside the lid
showing what worked what, and there appeared to be three gaps in the
box where there should have been two fuses and a relay for the ABS.
Great, I thought, I've found the fault. My joy was short lived though,
because when I tried to insert the ABS fuses in the places where I
thought they should be, there were no connectors in the slots and the
fuses just wiggled around rather aimlessly. So I'm wondering if the
fusebox design was modified for the Jeep Cherokee 2001 but someone
forgot to update the diagram.

I was unable to get a workshop manual for this model and date at our
local Canadian Tire but I'm going to try to order one over the
Internet.

It looks like my jeep is heading for a date with Jeeps-R-Us to be
fixed, but if anyone has any further comments / suggestions I'd be
grateful for them, bearing in mind that I live in Lourdes, Western
Newfoundland and there is no Jeeps-R-Us around here.

Doug W - you suggested cleaning the ABS computer connector. I wasn't
able to identify it under the hood, but if you can give me an idea
where it is and what it looks like I can try that.

Thanks.

We do appreciate follow ups, you are right there.

Umm, are you 'sure' you actually 'have' ABS????

Doesn't sound like it to me.....

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Peter wrote:
>
> Good afternoon. I'm just posting a followup to our discussion about my
> Jeep Cherokee ABS problem because I know you guys really, really care
> about whether I got it to work or not.
>
> Most of you suggested stomping hard instead of gently on the brakes.
> After the next snowfall I tried this, but whether I stomped gently or
> hard, it made no difference, there seemed to be no response of any kind
> from the ABS. I then read the section about ABS in my glovebox owner's
> guide (should have RTFM to begin with, I suppose) and it said that the
> ABS light should come on for a couple of seconds when you turn on the
> ignition. It isn't lighting up at switch on or at any other time,
> suggesting there really is a fault and it isn't just my imagination.
>
> I opened a box of electrics under the hood, looking for clues, and it
> was full of relays and fuses. There was a diagram inside the lid
> showing what worked what, and there appeared to be three gaps in the
> box where there should have been two fuses and a relay for the ABS.
> Great, I thought, I've found the fault. My joy was short lived though,
> because when I tried to insert the ABS fuses in the places where I
> thought they should be, there were no connectors in the slots and the
> fuses just wiggled around rather aimlessly. So I'm wondering if the
> fusebox design was modified for the Jeep Cherokee 2001 but someone
> forgot to update the diagram.
>
> I was unable to get a workshop manual for this model and date at our
> local Canadian Tire but I'm going to try to order one over the
> Internet.
>
> It looks like my jeep is heading for a date with Jeeps-R-Us to be
> fixed, but if anyone has any further comments / suggestions I'd be
> grateful for them, bearing in mind that I live in Lourdes, Western
> Newfoundland and there is no Jeeps-R-Us around here.
>
> Doug W - you suggested cleaning the ABS computer connector. I wasn't
> able to identify it under the hood, but if you can give me an idea
> where it is and what it looks like I can try that.
>
> Thanks.

Are you sure your model is supposed to have ABS?

Is it listed on your build sheet?

You can get a build sheet from your (no so) local Jeep dealership PARTS
department or via Jeep customer Assistance via e-mail (both at No Charge)
http://www.jeep.com/universal/J/inde...tr=wccs&prefix



"Peter" > wrote in message
oups.com...
> Good afternoon. I'm just posting a followup to our discussion about my
> Jeep Cherokee ABS problem because I know you guys really, really care
> about whether I got it to work or not.
>
> Most of you suggested stomping hard instead of gently on the brakes.
> After the next snowfall I tried this, but whether I stomped gently or
> hard, it made no difference, there seemed to be no response of any kind
> from the ABS. I then read the section about ABS in my glovebox owner's
> guide (should have RTFM to begin with, I suppose) and it said that the
> ABS light should come on for a couple of seconds when you turn on the
> ignition. It isn't lighting up at switch on or at any other time,
> suggesting there really is a fault and it isn't just my imagination.
>
> I opened a box of electrics under the hood, looking for clues, and it
> was full of relays and fuses. There was a diagram inside the lid
> showing what worked what, and there appeared to be three gaps in the
> box where there should have been two fuses and a relay for the ABS.
> Great, I thought, I've found the fault. My joy was short lived though,
> because when I tried to insert the ABS fuses in the places where I
> thought they should be, there were no connectors in the slots and the
> fuses just wiggled around rather aimlessly. So I'm wondering if the
> fusebox design was modified for the Jeep Cherokee 2001 but someone
> forgot to update the diagram.
>
> I was unable to get a workshop manual for this model and date at our
> local Canadian Tire but I'm going to try to order one over the
> Internet.
>
> It looks like my jeep is heading for a date with Jeeps-R-Us to be
> fixed, but if anyone has any further comments / suggestions I'd be
> grateful for them, bearing in mind that I live in Lourdes, Western
> Newfoundland and there is no Jeeps-R-Us around here.
>
> Doug W - you suggested cleaning the ABS computer connector. I wasn't
> able to identify it under the hood, but if you can give me an idea
> where it is and what it looks like I can try that.
>
> Thanks.
>