Instrument panel brake warning lights
#1
08-05-2015, 07:07 AM
Instrument panel brake warning lights
Hi everyone, I have some issues with instrument panel brakewarning lights.Being an XJS novice I wouldappreciate any guidance or words of wisdom. Car is a 1990, 3.6 XJS coupe.
Didn’t realise the car had ALBS when I bought it and thenrealised the dash warning light wasn’t coming on at all, even at start up.Replaced the blown bulb and this is nowilluminated all the time.Maybe this isan example of “if it is broke don’t fix it!”Just joking as clearly this has to be sorted.
I have manuals to study but understand the system to bebasically wheel sensors, connecting wires and an ALBS brain.So, in your collective experience, where dothe majority of problems occur i.e., where should I start?Also I believe I read somewhere that it ispossible to interrogate the ALBS brain and establish fault codes but can’tremember where I saw this – has anyone else seen anything similar?
A further question; Before I replaced the ALBS bulb theother brake warning light on the panel would come on at ignition turn on, the brakepump would hum to build up pressure and 20 seconds later the pump would ceaseand the warning light go out as it all should. Hooray! Problem is since I temporarilyreplaced the ALBS bulb the brake warning light no longer comes on even though Ican still hear the pump still doing its stuff.Is there some odd connectivity between the ALBS and brake warningsystems or have I somehow disturbed the wiring to the latter?
Despite all of the above the brakes are powerful, pull thecar up in a straight line and the pedal feels normal.
Thanks for reading this far and would be grateful for anyadvice.
Cheers,
LeeP
Didn’t realise the car had ALBS when I bought it and thenrealised the dash warning light wasn’t coming on at all, even at start up.Replaced the blown bulb and this is nowilluminated all the time.Maybe this isan example of “if it is broke don’t fix it!”Just joking as clearly this has to be sorted.
I have manuals to study but understand the system to bebasically wheel sensors, connecting wires and an ALBS brain.So, in your collective experience, where dothe majority of problems occur i.e., where should I start?Also I believe I read somewhere that it ispossible to interrogate the ALBS brain and establish fault codes but can’tremember where I saw this – has anyone else seen anything similar?
A further question; Before I replaced the ALBS bulb theother brake warning light on the panel would come on at ignition turn on, the brakepump would hum to build up pressure and 20 seconds later the pump would ceaseand the warning light go out as it all should. Hooray! Problem is since I temporarilyreplaced the ALBS bulb the brake warning light no longer comes on even though Ican still hear the pump still doing its stuff.Is there some odd connectivity between the ALBS and brake warningsystems or have I somehow disturbed the wiring to the latter?
Despite all of the above the brakes are powerful, pull thecar up in a straight line and the pedal feels normal.
Thanks for reading this far and would be grateful for anyadvice.
Cheers,
LeeP
#2
08-05-2015, 07:37 AM
Veteran Member
LeeP,
ABS problems seem to be the flavour of the month here!
The basis on which one or both of the lights will illuminate is explained in the Service Manual.
If the accumulator is already at full pressure before you turn on the ignition, you might not see the Brake Warning Light. If the ABS light is on all the time, then theoretically, the ABS has been disabled because of a fault in teh system and you do not have ABS capability.
I would:
- Read through the manual in order that you understand teh system and the light illumination conditions.
- Check the Brake warning light bulb (in case that's now blown!)
- Run through the 32 diagnostic tests as defined in the Service Manual
Then report back with your findings!
Good luck
Paul
ABS problems seem to be the flavour of the month here!
The basis on which one or both of the lights will illuminate is explained in the Service Manual.
If the accumulator is already at full pressure before you turn on the ignition, you might not see the Brake Warning Light. If the ABS light is on all the time, then theoretically, the ABS has been disabled because of a fault in teh system and you do not have ABS capability.
I would:
- Read through the manual in order that you understand teh system and the light illumination conditions.
- Check the Brake warning light bulb (in case that's now blown!)
- Run through the 32 diagnostic tests as defined in the Service Manual
Then report back with your findings!
Good luck
Paul
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leep123 (08-05-2015)
#3
08-05-2015, 07:54 AM
Veteran Member
Hi
If you've only just bought the Car, it sounds like someone may have had a problem with the ABS side of the Brakes.
In which case the Car may have taken a sudden unexpected dive to the other side of the road.
Not an exhaustive list of things that can occur with a faulty ABS but it can be one of them.
One of the most Common Causes is failing to leave the Bleed Screws undone and not clamping the Rubber Brake Hoses, when changing Brake Pads.
Where someone may have levered the Pistons back into the Caliper without doing so.
Which can have the effect of forcing Contaminated Brake Fluid the wrong way back up the System, which can totally wreck the Valves in the
Master Cylinder Actuator.
After which it could leave you with a major problem to sort out.
If I had to take a 'Wild Guess' there could be a possibility, that in the event that has happened, someone may have disabled the ABS side of the Brakes.
Which would also have the effect of the ABS light always being on, unless of course they removed the Bulb, or replaced it with a dud one.
Under the dash on the Passenger side is a Fuse Box, at least that's where it is on a V12 (so maybe the same)
Where if you remove the cover, you should be able to see, 2 X 30 amp fuses, all on their own.
One is for the Brake Pump and the other one Controls the ABS.
Have a look and see if the Fuse for the ABS has Blown or maybe it is Missing altogether.
Either of which, would explain the ABS light being on all the time, or at least it would have been, if the ABS light bulb had been working, as it is now.
On no account remove the Fuse for the Brake Pump, or you will disable all the Brakes on the Car.
So first check the ABS Fuse and then report back what you find.
If you've only just bought the Car, it sounds like someone may have had a problem with the ABS side of the Brakes.
In which case the Car may have taken a sudden unexpected dive to the other side of the road.
Not an exhaustive list of things that can occur with a faulty ABS but it can be one of them.
One of the most Common Causes is failing to leave the Bleed Screws undone and not clamping the Rubber Brake Hoses, when changing Brake Pads.
Where someone may have levered the Pistons back into the Caliper without doing so.
Which can have the effect of forcing Contaminated Brake Fluid the wrong way back up the System, which can totally wreck the Valves in the
Master Cylinder Actuator.
After which it could leave you with a major problem to sort out.
If I had to take a 'Wild Guess' there could be a possibility, that in the event that has happened, someone may have disabled the ABS side of the Brakes.
Which would also have the effect of the ABS light always being on, unless of course they removed the Bulb, or replaced it with a dud one.
Under the dash on the Passenger side is a Fuse Box, at least that's where it is on a V12 (so maybe the same)
Where if you remove the cover, you should be able to see, 2 X 30 amp fuses, all on their own.
One is for the Brake Pump and the other one Controls the ABS.
Have a look and see if the Fuse for the ABS has Blown or maybe it is Missing altogether.
Either of which, would explain the ABS light being on all the time, or at least it would have been, if the ABS light bulb had been working, as it is now.
On no account remove the Fuse for the Brake Pump, or you will disable all the Brakes on the Car.
So first check the ABS Fuse and then report back what you find.
Last edited by orangeblossom; 08-05-2015 at 07:56 AM.
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leep123 (08-05-2015)
#4
08-05-2015, 09:15 AM
Jaguar ABS Here is a link to ABS codes and how to determine where the problem is located. I used this procedure on my 93 XJS and found that the two front ABS sensor cables were faulty. Replaced both and now all it fine in the ABS system.
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leep123 (08-05-2015)
#5
08-05-2015, 01:47 PM
Thanks
Thanks guys for these really useful replies. I'll start working through the options at the weekend and let you know how I get on.
As a Jaguar novice I'm really pleased I discovered the forum as I have learnt so much in a few weeks. Hopefully I will be able to pay back the knowledge one day.
Cheers,
LeeP
As a Jaguar novice I'm really pleased I discovered the forum as I have learnt so much in a few weeks. Hopefully I will be able to pay back the knowledge one day.
Cheers,
LeeP
#6
08-09-2015, 10:06 AM
Hi
If you've only just bought the Car, it sounds like someone may have had a problem with the ABS side of the Brakes.
In which case the Car may have taken a sudden unexpected dive to the other side of the road.
Not an exhaustive list of things that can occur with a faulty ABS but it can be one of them.
One of the most Common Causes is failing to leave the Bleed Screws undone and not clamping the Rubber Brake Hoses, when changing Brake Pads.
Where someone may have levered the Pistons back into the Caliper without doing so.
Which can have the effect of forcing Contaminated Brake Fluid the wrong way back up the System, which can totally wreck the Valves in the
Master Cylinder Actuator.
After which it could leave you with a major problem to sort out.
If I had to take a 'Wild Guess' there could be a possibility, that in the event that has happened, someone may have disabled the ABS side of the Brakes.
Which would also have the effect of the ABS light always being on, unless of course they removed the Bulb, or replaced it with a dud one.
Under the dash on the Passenger side is a Fuse Box, at least that's where it is on a V12 (so maybe the same)
Where if you remove the cover, you should be able to see, 2 X 30 amp fuses, all on their own.
One is for the Brake Pump and the other one Controls the ABS.
Have a look and see if the Fuse for the ABS has Blown or maybe it is Missing altogether.
Either of which, would explain the ABS light being on all the time, or at least it would have been, if the ABS light bulb had been working, as it is now.
On no account remove the Fuse for the Brake Pump, or you will disable all the Brakes on the Car.
So first check the ABS Fuse and then report back what you find.
If you've only just bought the Car, it sounds like someone may have had a problem with the ABS side of the Brakes.
In which case the Car may have taken a sudden unexpected dive to the other side of the road.
Not an exhaustive list of things that can occur with a faulty ABS but it can be one of them.
One of the most Common Causes is failing to leave the Bleed Screws undone and not clamping the Rubber Brake Hoses, when changing Brake Pads.
Where someone may have levered the Pistons back into the Caliper without doing so.
Which can have the effect of forcing Contaminated Brake Fluid the wrong way back up the System, which can totally wreck the Valves in the
Master Cylinder Actuator.
After which it could leave you with a major problem to sort out.
If I had to take a 'Wild Guess' there could be a possibility, that in the event that has happened, someone may have disabled the ABS side of the Brakes.
Which would also have the effect of the ABS light always being on, unless of course they removed the Bulb, or replaced it with a dud one.
Under the dash on the Passenger side is a Fuse Box, at least that's where it is on a V12 (so maybe the same)
Where if you remove the cover, you should be able to see, 2 X 30 amp fuses, all on their own.
One is for the Brake Pump and the other one Controls the ABS.
Have a look and see if the Fuse for the ABS has Blown or maybe it is Missing altogether.
Either of which, would explain the ABS light being on all the time, or at least it would have been, if the ABS light bulb had been working, as it is now.
On no account remove the Fuse for the Brake Pump, or you will disable all the Brakes on the Car.
So first check the ABS Fuse and then report back what you find.
So now, as suggested by other replies, I have to start trying to establish specific error codes.
Cheers,
LeeP
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orangeblossom (08-09-2015)
#7
08-30-2015, 09:57 AM
Fault code reading problems
Hi folks,
So, I found the diagnostic socket in the boot near the ecu and connected a jumper (bent paperclip) between the black and brown/pink female outlets as recommended on p 456 of Kirby Palm's book.
Problem is the dash warning light remains stubbornly on and refuses to blink (no matter how much I stare at it!). I have not driven the car for a week but I am presuming that the codes are stored in the ecu unit for at least this length of time.
Does the failure of the warning light to blink indicate something sinister within the ecu or am I going wrong somewhere? I have checked both 30 amp fuses and they are OK.
All suggestions appreciated.
Cheers,
LeeP
So, I found the diagnostic socket in the boot near the ecu and connected a jumper (bent paperclip) between the black and brown/pink female outlets as recommended on p 456 of Kirby Palm's book.
Problem is the dash warning light remains stubbornly on and refuses to blink (no matter how much I stare at it!). I have not driven the car for a week but I am presuming that the codes are stored in the ecu unit for at least this length of time.
Does the failure of the warning light to blink indicate something sinister within the ecu or am I going wrong somewhere? I have checked both 30 amp fuses and they are OK.
All suggestions appreciated.
Cheers,
LeeP
The following users liked this post:
1100me (08-31-2015)
Trending Topics
#8
08-30-2015, 04:01 PM
The car needs to be driven at least 10 or more minutes, prior to connecting the paper-clip. Once you have done the drive. Connect the clip correctly, turn on the ignition, not starting the motor. Read the blinks. The first will be either a one or two blink. Then approx. 6 secs, a two or three blink. Here is a website that will assist you in the code readings. Jaguar ABS. This process helped me narrow down where the ABS was faulting.
#10
09-07-2015, 03:49 PM
The car needs to be driven at least 10 or more minutes, prior to connecting the paper-clip. Once you have done the drive. Connect the clip correctly, turn on the ignition, not starting the motor. Read the blinks. The first will be either a one or two blink. Then approx. 6 secs, a two or three blink. Here is a website that will assist you in the code readings. Jaguar ABS. This process helped me narrow down where the ABS was faulting.
LeeP
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