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ABS light constantly 'ON'

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I have a 1996 300 series Discovery ES model (everything electric)

I have recently had a new drivers side swivel hub fitted and a new ABS sensor, the mechanic could not get the ABS warning light to go off despite setting it up correctly.

I have checked the vehicle out since it was returned to me and found that the rear windows won't operate and the front passenger door will not unlock from the remote keyfob.

I also found that the yellow half of the ABS sensor connector (the part fitted to the wiring loom) had been cut off, this had been soldered back on but the wires poorly insulated. I have since rectified this but the warning light is still on. Having looked at the connector it appears to be polarised, but the two wires going to it are both green. Could it be that the wires have been connected incorrectly, and is there some remote fuse that has blown affecting the windows and passenger door locking device. I have checked every fuse I can find but they are all intact.

I would appreciate any help on this problem as I cannot find an answer.

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Was the light on before the change or has it only come on since having the work done? There is a fault diagnostic method using a paper clip on one of the forums but can't remember which.

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First of all, ABS is a safety critical system and should not be having cut wires soldered up - have the garage replace the sensor they damaged at their cost under threat, if necessary, of reporting to trading standards and all the local papers and Land Rover magazines/forums. I suspect that sensor has been buggered by the damage. However, it is possible that the sensor merely needs repositioning - it should be pressed in by fingers only as far as it will go and the steering should then be moved from lock to lock to set the sensor's distance from the CV bell. If it's too far from the bell, it won't read the sensor ring on the bell and will not sense the wheel rotation speed.

Just in case you aren't aware of it, the rear windows have a child-lock button to deactivate the switches on the doors, but the switches on the cubby box should still operate them regardless. This is the button with the amber window symbol in the middle of the four window switches on the cubby box - it should be pressed in to enable the rear switches and out to disable them. If the windows don't work as above, there is a fault.

If the ABS light, central locking and rear window faults occurred at the garage, they have a legal duty to repair their damage. They may have spiked the ECUs by letting the battery run too low a voltage (leaving the ignition on and doors open while running tests will do that), or they may have caused problems by jumpstarting it or using it to jump another vehicle. It needs diagnostic tools like Test Book or Autologic, and if they don't have these facilities, the garage will have to pay a garage with those tools for their time to run the tests.

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Thank you all for the replies I'll answer in sequence:


I have found the information you mentioned, copied it and intened to try it this weekend, I'll keep you posted.


Thank you for the info. I'll check it out, maybe the same as that I've already found, but you can't have too much good info.


I agree with your thoughts on this entirely but I have been using this garage for several years (friend of my daughters) so I don't really want to get heavy handed or go down the legal route, however, I won't use them again. They certainly won't get any recommendations from me.

I have tried the child-lock button for my rear windows, no luck, I will investigate further.

I didn't know the steering had to be rotated from lock to lock. I will try this and also the 'paper clip' method suggested by ballcock

Thanks again,


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A 1996 Discovery is still farly 'plugging into a computer' free - as mentioned above, the ABS can be reset quite easily, and will flash a fauly code in process of resetting.

Once the ABS ECU has detected a fault, it will keep the ABS light lit until reset, even if you have fixed the fault.

I've had mine go with a faulty brake light switch, and a sensor out of alignment, and the best one was when one of the relays had come off its holder, and was upside down, filled up with water (from the normal windscreen leak) and actually caused a continuous drain on the battery.

After several flat batteries tried to decipher code, and got a none existant one tthat pointed towards the voltage. In a process of elimination found the circuit with the drain was the ABS so thought I would remove the relay, to discover a rusty water filled current draw!

Changed relay and was back in business.

Re the back windows, they are entirely ECU free, apart from using the timed output from the front window ECU so you can operate them for a short time after turning the ignition off, before you open a door.

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