[xj-s] ABS

XJ-S
1

After reading the recent threads on ECU reliability. And also not recieving
a response requesting where I could send my ABS ecu. I decided to reheat
the solder joints. Imagine my joy when 10-15 sec’s starting the car the abs
light went out and I had ABS again. Only to be dissappointed about 1 min
later when the light came on. If I switch the engine off and start up again
I have ABS for 1- 1.05 mins. Can anyone offer a suggestion as to what the
prob might be (I have been trying to solve my ABS prob for several months
now)
TIA
Gerry Halpern
Melbourne Aust
88 XJ-S (UK series)

2

In message <l03130300b23d202b1972@[210.15.250.151]> Gerry Halpern writes:

If I switch the engine off and start up again
I have ABS for 1- 1.05 mins.

This may be a long shot, but anyway - have you checked connection and operation
of the pressure switch on the pump unit ? One minute and a bit sounds like
the maximum time it should take for the pump to pressurize the acumulator,
perhaps there is a timeout after that if the system doesn’t get suitable
feedback from the pressure switch.

Also, have you tried the intermittent fault readout procedure ? It’s
in the ROM, involves a bent paperclip, a notepad and some patience.

Regards,–
Stefan Schulz
@Stefan_Schulz
'88 XJ-S V12, UK version

3

All

When did the ABS production start for the XJ-S?

Thanks

Ralph
'88XJ-S

4

Ralph: I have never seen an 87 or 88 car with ABS on it, but that
doesn’t mean that they did not have it in Europe. All the cars I have
seen are 89 up.
Chad Bolles Jaguar Performance, Inc 306 Valcour Rd Columbia SC 29212
803 798 3044 FAX 803 798 4512

Ralph W. Brooks wrote:>

All

When did the ABS production start for the XJ-S?

Thanks

Ralph
'88XJ-S

5

Chad and John

Got your posts and decided to check the Mfg. Plate.

My “88” was mfg’d in July, 1987. Guess that tells the story - no ABS.

Thanks for the replies.

Ralph
'88XJ-S

Chad Bolles wrote:>

Ralph: I have never seen an 87 or 88 car with ABS on it, but that
doesn’t mean that they did not have it in Europe. All the cars I have
seen are 89 up.
Chad Bolles Jaguar Performance, Inc 306 Valcour Rd Columbia SC 29212
803 798 3044 FAX 803 798 4512

Ralph W. Brooks wrote:

All

When did the ABS production start for the XJ-S?

Thanks

Ralph
'88XJ-S

6

Ralph,
My car is an 88 xjs v12 Europe spec with ABS, and out here at the moment the
temp averages 43c in the shade,
no problems with the brakes so far!
regards
Tom----- Original Message -----
From: Ralph W. Brooks rwb@qadas.com
To: Lamborghini@worldnet.att.net
Cc: XJS Forum XJ-S@jag-lovers.org
Sent: Saturday, May 29, 1999 9:54 PM
Subject: Re: [xj-s] ABS

Chad and John

Got your posts and decided to check the Mfg. Plate.

My “88” was mfg’d in July, 1987. Guess that tells the story - no ABS.

Thanks for the replies.

Ralph
'88XJ-S

Chad Bolles wrote:

Ralph: I have never seen an 87 or 88 car with ABS on it, but that
doesn’t mean that they did not have it in Europe. All the cars I have
seen are 89 up.
Chad Bolles Jaguar Performance, Inc 306 Valcour Rd Columbia SC 29212
803 798 3044 FAX 803 798 4512

Ralph W. Brooks wrote:

All

When did the ABS production start for the XJ-S?

Thanks

Ralph
'88XJ-S

7

The microfiche isn’t very clear, and doesn’t give a serial range, but it
looks like ABS started on the XJ-S in 1988-1/2.

Gregory Wells
Coventry West, Inc.
New, Rebuilt, & Used Jaguar Parts
http://www.coventrywest.com
800-331-2193 x103----------

From: Chad Bolles Lamborghini@worldnet.att.net
To: Ralph W. Brooks rwb@qadas.com
Cc: XJS Forum XJ-S@jag-lovers.org
Subject: Re: [xj-s] ABS
Date: Saturday, May 29, 1999 4:50 PM

Ralph: I have never seen an 87 or 88 car with ABS on it, but that
doesn’t mean that they did not have it in Europe. All the cars I have
seen are 89 up.
Chad Bolles Jaguar Performance, Inc 306 Valcour Rd Columbia SC 29212
803 798 3044 FAX 803 798 4512

Ralph W. Brooks wrote:

All

When did the ABS production start for the XJ-S?

Thanks

Ralph
'88XJ-S

8

90 xjs v12 conv.

Unfortunately, my ABS is shot.

The yellow light comes on right after start-up and stays on while driving.
I know that most people in the list know nothing about the ABS, as well as
do not have ABS. So, chances are dim that i will find the problem.
My normal brakes are good though and the brake petal has pressure, so it is
only the ABS that malfunctions. I recently did a brake fluid change.

Anyway, at least I want to identify the faulty component.

Here is a list of all the individual components - that I know of - that
make up the ABS system on my car:-------------------------

  1. ABS Pump.

  2. ABS pump fuse. This is situated in the passenger footwell. There are 2
    30A fuses related to the ABS.

  3. ABS Accumulator

  4. ABS Computer (ECU)

  5. ABS Valve

  6. ABS sensors (near wheels),

  7. ABS electrical connections.

Can someone tell me at least where these items are situated on the car?

Also, I want to clean all ABS electrical connections. Where are they,
please? How do I clean electrical connections? WD40?

Thanks,
Chris.

9

My advice is to remove the light bulb on the dash and forget you ever had
ABS. It’s a fail-safe system so your brakes should work just fine without
it. Those things are just money down a rat hole.

Cheers,
BryOn Wed, 23 Aug 2000 christky@bellatlantic.net wrote:

90 xjs v12 conv.

Unfortunately, my ABS is shot.

The yellow light comes on right after start-up and stays on while driving.

10

90 xjs v12 conv.

I had brake pads changed and flushed the brake fluid, and right after the
job was done I experienced the ABS failure. I think that the mechanic who
did the brake job forced contaminated fluid back up the lines and into the
master control system while pressing back the calipers when installing new
pads.

It does not explain it any other way, my ABS failing just like that out of
the blue. It was fine before the brake job and I was testing it once a
month, feeling the pumping of the brakes. It used to work perfectly.

I believe some magic was done while the car was at the shop for brake
service and my ABS failed.

I don’ t know whta to do now.

Chris.

11

I had brake pads changed and flushed the brake fluid, and right after the
job was done I experienced the ABS failure. I think that the mechanic who
did the brake job forced contaminated fluid back up the lines and into the
master control system while pressing back the calipers when installing new
pads.

Well, I’ll try again in the hopes that maybe you’ll listen. GET THE ROM!
ACTUALLY READ IT! If the system was properly flushed and bled, there is no
reason to suspect that this was the cause of your problem. However, it has
been known to exascerbate a problem that was already there. I assume you got
the trouble codes from the ABS computer, right? The most common problems are
the wheel sensors that can become occluded with grease and dirt.

It does not explain it any other way, my ABS failing just like that out of
the blue. It was fine before the brake job and I was testing it once a
month, feeling the pumping of the brakes. It used to work perfectly.

And it can again if you get it worked on by somebody familiar with the
system.

I believe some magic was done while the car was at the shop for brake
service and my ABS failed.

Magic?

I don’ t know whta to do now.

GET THE ROM! READ IT! FIND A COMPETENT MECHANIC!
Jeb Boyd
V-12 Engine List Admin
British Car Junkie
Dillsburg, Pa
@Lisa_Jeb_BoydFrom: christky@bellatlantic.net

12

Chris,
First - listen to Jeb. He is the Teves ABS expert. You should by the ROM
because you need it anyway. Unfortunately the ROM does not cover all the
details about your MY but it shows the later model ABS in detail. You can
use most of the repair instructions as described also for your MY but the
electrical ECU pinout and error codes are only for later models. I recommend
you to go the easiest way first and check the wheel sensor wires. It seems
to me your shop broke one (maybe more) sensor wire. In my case I’d ABS
problems after changing front wheel bearings - the shop killed one sensor
wire. If you need the correct electrical pinout for your ECU check the
archives. I posted my results there in June. If you can’t find it contact me
off list.

Andreas
89XJ-S----- Original Message -----
From: christky@bellatlantic.net
To: xj-s@jag-lovers.org
Sent: Wednesday, August 23, 2000 10:17 PM
Subject: [xj-s] ABS

90 xjs v12 conv.

I had brake pads changed and flushed the brake fluid, and right after the
job was done I experienced the ABS failure. I think that the mechanic who
did the brake job forced contaminated fluid back up the lines and into the
master control system while pressing back the calipers when installing new
pads.

It does not explain it any other way, my ABS failing just like that out of
the blue. It was fine before the brake job and I was testing it once a
month, feeling the pumping of the brakes. It used to work perfectly.

I believe some magic was done while the car was at the shop for brake
service and my ABS failed.

I don’ t know whta to do now.

Chris.

13

The ABS ECU used two methods of checking whether the ABS is functional or
not.
Firstly it carries out a static system check when the ignition is turned on,
this is the time when your warning light will be illuminated for a while
before it is extinguished. During this time it checks the resistance of all
the wheel sensors and probably a few other things as well.
Secondly it carries out a dynamic system check once the vehicle is moving
faster that 5 MPH (roughly). This time it checks all the wheel sensors again
but instead of checking the resistance, it checks for the presence of pulses
from the wheel sensors.
The warning light on the dashboard will come on untill the ECU is satisfied
that all the checks are good. This light has to be forced to turn off by the
ECU, the only other way is to remove the bulb. I don’t think even removing
the ECU will turn the light off but I could be wrong.

There are a couple of quick checks you can do to test out the front wheel
sensors and the ECU.
If you disconnect the front wheel sensors (connections located in the engine
bay on both inner wings just below and rearwards of the front suspension
mounts) and measure the resistance of the sensors with an ohmmeter you
should see between 800 and 1200 ohms (or there abouts, a little bit either
way won’t hurt). While you have the sensors disconnected, place a 1000 ohm
resistor across the connections on the wires that lead back to the ECU. You
will need an assistant here 'cos the connections here are the pins of the
connector. Then turn on the ignition and wait for the usual time before the
light normally goes out, I think the book says something like a maximum of
20 seconds. If the light goes out then the wiring and ECU is OK.
Repeat this procedure for both front wheels. This will tell you if either of
the front sensors are shot or if the ECU is not behaving.
The same procedures can be applied to the rear wheel sensor but I don’t know
where the connector is.

DO NOT clean electrical connections with WD40. WD40 is petroleum based and
will leave an oily residue. Use an alcohol based cleaner of some
description, I find vodka does very nicely and it has another more pleasant
use too, once you have cleaned your contacts, you can celebrate with it.

Hope this shed a bit of light on it for you.

Paul----- Original Message -----
From: christky@bellatlantic.net
To: xj-s@jag-lovers.org
Sent: 24 August 2000 01:10
Subject: [xj-s] ABS

90 xjs v12 conv.

Unfortunately, my ABS is shot.

The yellow light comes on right after start-up and stays on while driving.
I know that most people in the list know nothing about the ABS, as well as
do not have ABS. So, chances are dim that i will find the problem.
My normal brakes are good though and the brake petal has pressure, so it
is
only the ABS that malfunctions. I recently did a brake fluid change.

Anyway, at least I want to identify the faulty component.

Here is a list of all the individual components - that I know of - that
make up the ABS system on my car:

  1. ABS Pump.

  2. ABS pump fuse. This is situated in the passenger footwell. There are
    2
    30A fuses related to the ABS.

  3. ABS Accumulator

  4. ABS Computer (ECU)

  5. ABS Valve

  6. ABS sensors (near wheels),

  7. ABS electrical connections.

Can someone tell me at least where these items are situated on the car?

Also, I want to clean all ABS electrical connections. Where are they,
please? How do I clean electrical connections? WD40?

Thanks,
Chris.

14

90 xjs v12 conv.

I talked to a specialist today about my ABS problem, and unfortunately,
without hesitation he pointed the source of the problem to the master
control system below the brake fluid reservoir, on the driver side.

I said “unfortunately” because that particular bolt- on piece, IS the one
costing $3,000 to replace.

My wheel sensors are fine and everything else appears to be fine. The ABS
simply does not get energized when the wheels lock because of a malfunction
in the master control unit.

I have already sensed the lack of ABS today: While braking hard when
someone cut me off, the right wheel locked and the left wheel kept braking.

It is prohibitively expensive to do this ABS job.

It will take a little used to to learn to brake effectively without ABS.
Seems that I have to simulate the ABS pumping myself every time one, or
both wheels lock during braking.

Chris.

15

I talked to a specialist today about my ABS problem, and unfortunately,
without hesitation he pointed the source of the problem to the master
control system below the brake fluid reservoir, on the driver side.

It seems odd that the actuator assembly would suddenly go bad when the only
thing that is different is that the system was flushed.

I said “unfortunately” because that particular bolt- on piece, IS the one
costing $3,000 to replace.

Yeah, STUPID expensive…so maybe you should have someone who REALLY
knows these systems look it over.

My wheel sensors are fine and everything else appears to be fine. The ABS
simply does not get energized when the wheels lock because of a
malfunction
in the master control unit.

If the ABS is doing nothing, then why doesn’t the car stop in a straight
line, only with the tires smoking? If the ABS was totally crippled, you
wouldn’t have that one side dive.

I have already sensed the lack of ABS today: While braking hard when
someone cut me off, the right wheel locked and the left wheel kept
braking.

Did it pull visciously to the one side? If so, I really don’t think the
actuator is necessarily bad.

It is prohibitively expensive to do this ABS job.

Maybe not, if you can get on the right track with your diagnosis and
repairs.

It will take a little used to to learn to brake effectively without ABS.
Seems that I have to simulate the ABS pumping myself every time one, or
both wheels lock during braking.

This is still a car. There is no reason to try and “simulate” the ABS. For
one thing, you couldn’t move your foot that fast. You may have something as
dumb as a regular hard part failure. If the ABS is actually off line, it
should perform like “normal” brakes, and not do anything strange.

Please find another person to inspect and assess your brakes. And make sure
that this person knows that this problem originated after somebody worked on
it, not out of the blue.
Cheers,
Jeb Boyd
V-12 Engine List Admin
British Car Junkie
Dillsburg, Pa
@Lisa_Jeb_BoydFrom: christky@bellatlantic.net

16

Just being curious - how did your specialist found out? Did he read error
codes? Did he check all four speed sensors for resistance?
I only want to know how a professional starts looking at a Teves ABS
problem.

Andreas----- Original Message -----
From: christky@bellatlantic.net
To: xj-s@jag-lovers.org
Sent: Thursday, August 24, 2000 9:05 PM
Subject: [xj-s] ABS

90 xjs v12 conv.

I talked to a specialist today about my ABS problem, and unfortunately,
without hesitation he pointed the source of the problem to the master
control system below the brake fluid reservoir, on the driver side.

I said “unfortunately” because that particular bolt- on piece, IS the one
costing $3,000 to replace.

My wheel sensors are fine and everything else appears to be fine. The ABS
simply does not get energized when the wheels lock because of a
malfunction
in the master control unit.

I have already sensed the lack of ABS today: While braking hard when
someone cut me off, the right wheel locked and the left wheel kept
braking.

It is prohibitively expensive to do this ABS job.

It will take a little used to to learn to brake effectively without ABS.
Seems that I have to simulate the ABS pumping myself every time one, or
both wheels lock during braking.

Chris.

17

I said “unfortunately” because that particular bolt- on piece, IS
the one costing $3,000 to replace.

It is only too apparent that the Book is not helpful enough when it
comes to ABS. And chances are poor it’s gonna get much better, since
I don’t have ABS in my '83.

If anyone happens to end up with a scrap ABS control unit – that big
expensive doohickey – how about shipping it to me? Maybe I’ll be
able to put together some better advice on servicing and maintaining
the contraption.

Y’know, ABS is NOT rare these days, even in GM cars. Perhaps we
should be looking into the possibility of yanking the control unit
out of a Chevy or something and fitting it into the XJ-S.

– Kirbert | Palm’s Postulate:
| If anything is to be accomplished,
| some rules must be broken.
| – Kirby Palm, 1979

18

Y’know, ABS is NOT rare these days, even in GM cars. Perhaps we
should be looking into the possibility of yanking the control unit
out of a Chevy or something and fitting it into the XJ-S.

Actually, Ford (well, Lincoln) used a very similiar Teves system in the
early '90s. Guess what…their actuator assembly is FOUR thousand! Nice
thought, though…I already tried that angle…RATS!
Cheers,
JebFrom: “Kirbert”

19

Chris:

The ABS on my '88 XJS has not worked for several years (failed computer unit). In my
opinion, ABS is overrated, especially here in the great white north with icy roads. I never
bothered to get it fixed. If yours works on one side only though, then that is not good.

Don
Calgary, '88, 160K km

20

On 24-08-00, christky@bellatlantic.net told us:

90 xjs v12 conv.

I talked to a specialist today about my ABS problem, and unfortunately,
without hesitation he pointed the source of the problem to the master
control system below the brake fluid reservoir, on the driver side.

If you are saying that he diagnosed without testing, then he is only a
specialist in extracting money from your wallet. Find someone who knows
about ABS.

regards,
Mike