I mentioned it in the first response – at the left side of the trunk over the left rear tire housing arch – you will have to remove the Trim panel between the spare and the metal brace, and reach up behind forward a bit behind the brace and you will find it (use a flash light first to find it)/ You will find the 3-socket test pigtail and the yellow ABS Main Relay there as well. The ABS main relay could be the problem if it has failed, as there will be no power to the ABS system. Richard, do you have an electrical schematic for your ABS, and do you have some knowledge of how to use a Volt-ohmeter?
In the pouring rain, I have opened the trunk and tried to locate the relay…I guess on a nicer day, tomorrow I will need to remove the spare tyre and hunt for it. Is it tucked behind the spare or the side of the trunk?
Thank you in advance.
I had same issues David with my 2000 Silverado. Intermittent on-off warning light. Cleaned up grounds, checked all the wheel sensors, etc. Lived with it for couple of years since brakes worked.
Finally bit the bullet and replaced the ABS control unit and haven’t had the light back since.
My 95 XJS abs pump failed and I replaced that. Otherwise no ABS issues with it. But also tend to avoid taking it out in rain. You know how finicky cats are about water.
Sounds like only your ABS system is at fault then. You would have no issues, until you tried slamming on your brakes and the car didn’t stop as fast as it should with ABS.
Good news…Lockheed 1 was correct. After installing a new fuel pump I was putting back in the spare tyre and noticed the back carpets were hanging. I glued them in all the way around and I must have dislodged the ABS relay. I made sure it was plugged in tightly and the issue is gone…Lights out.
If you go back and read the responses to you in this thread, you will see that others have told you that the pigtail with the red plug does not plug into anything – it is merely used for testing the ABS system and will give you a blinking light response to identify the fault or faults. The previous posters have also given you a description of how to read those light flashes – that description may be downloadable. The only relay on that side connected to the ABS controller is yellow, and located slightly up (further forward) than the ABS ECU. You will have to unfasten the ABS ECU and move it down towards you to get access to that relay – see link below… Any time you disconnect a component is an opportunity to use an electrical contact cleaner on the plug before reconnecting. Them. Please go back and read the relevant postings.
Hello
I have a problem with my xjs wonderful teve iii brake system . I have found the pig tale in the trunk short out black and brown/pink wire but get no reading on the system at all. both light are on constant no flashes or etc. Key in position 2 . i have testes the brakes on each corner . all are working fine ,bleed the system per procedure doing rear first key on then off doing each rear then front. i did notice I am getting a lot of air in the system no matter how many times i have bleed the system . Anyone fill me in what to look at ?
Hello again. The lights came back on. I removed the ABS controller and the only relay is see is a Black Siemens V23134-A55-X80 which when googled comes back to an all purpose 5 pin relay. The one you sent information about was a DAC4506 which is a three pin. There are no other relays in that area. I wonder if someone replace the 4506 with the Siemens relay at one point in time.
I am lost at this point and asking for your knowledge.
Please advise and thank you in advance, a mechanic I am not.
I mentioned it in the first response – at the left side of the trunk over the left rear tire housing arch – you will have to remove the Trim panel between the spare and the metal brace, and reach up behind forward a bit behind the brace and you will find it (use a flash light first to find it)/ You will find the 3-socket test pigtail and the yellow ABS Main Relay there as well. The ABS main relay could be the problem if it has failed, as there will be no power to the ABS system. Richard, do you have an electrical schematic for your ABS, and do you have some knowledge of how to use a Volt-ohmeter?
What’s odd is I viewed another diagram of the XJS and it showed two relays sitting next to the master cylinder, and one of them was the DAC 4506. Odd indeed.
First I would like to apologize for saying that the Main Relay (DAC7151) by the ABS ECU in the trunk (boot) was yellow. That relay could be gray or black, but should have five terminals. On the other hand, the yellow relay (DAC4506) is the ABS pump relay and located on the passenger side relay / fuse panel, and only has four distinctive terminals. Its been a while since I have had any dealings with the Teves III. I have no idea what relays you are talking about that are near the master cylinder. There is only ONE (1) yellow relay in the whole car, and it is located on the passenger side Fuse / Relay panel.
Your problem is not likely to be the ABS ECU or the Main Relay in the trunk – I don’t know that I have heard of a failure of either one. If the main relay had failed, you would not have an amber ABS light or a Red brake light (not the red parking brake light) because if the main relay had failed no part of the ABS system would be powered. When You have both the amber ABS light and the Red brake light, you have no brake pump operation to pressurize the system. You should be able to hear the brake pump run when you first turn the key to run (not start) the first start of the day. You should see the amber ABS light and the Red Brake light. As the pump builds pressure, the amber light will extinguish first and the red brake light will then go out and the pump will shut off. If you don’t hear the pump run and the light don’t go out – you have to find out why the pump isn’t running. Have you checked both 30 amp fuses for the ABS and brake pump at the passenger side fuse / relay panel? Is there 12V at each end of the fuses with the ignition key in the run position? Open the hood (bonnet) and pull the ABS pump plug and make sure you have 12V across the plug with the key in the run position. If not, the Brake Pump Relay (Yellow) is at fault. If yes, put your ohmmeter leads across the Pump terminals and see what the resistance of the pump motor windings – you should get some value of ohms – if not, you have a faulty pump motor.
There can be other reasons you don’t have power at the ABS pump motor – a faulty ABS combination pressure switch (located on the pump module - (on the ’89 XJS, it is normally a black top switch with 5 terminals, on later models it is a blue topped switch with 5 terminals) and a faulty brake fluid reservoir switch (or not enough fluid in the reservoir) could also cause the pump to not run. I don’t recall anyone ever having a problem with the reservoir switches. So, the most likely culprits here are the ABS Pump Relay (yellow), an the ABS Combination Pressure switch.
That’s my memory dump for now. To fill the gaps, I will attach a trouble shooting (test) guide, the guide for using the three pin test pigtail in the trunk, and the ABS schematic for the ’89 XJS. They may be too large to attach all to one message, and may come in additional message or messages as necessary. Please read them and follow them – and if you don’t yet have Kirby Palms “Experience in a Book”, get It and/or ask one of us for it!!!
In sum, read the information and follow through on the tests. If you don’t feel capable of doing that you need to find a shop that can do the work for you. It doesn’t work to just throw some guesses at the wall and see if some will solve your problem, nor can we help you much if you have not given us meaningful answers rather just guesses – we can tell what they are.
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