Landrover discovery td5 traction control coming on while driving on road

SOURCE: I have Landrover Discovery TD5 and the ABS and TC

Sounds like a faulty Diff Lock switch to me.
Most of the D2 models till late 03 model year use a version of firmware on the SLABS ECU that when diff-lock is detected puts the ABS and Traction Control systems into a lower response mode. Late model vehicles came with factory fit diff-lock linkages as a option, and the firmware was revised to allow this to operate in conjunction with the traction control.
Therefore ABS and TC illuminating (but with no HDC) means your TC/ABS is in the lower performing mode, and your diff-lock may be in, but more likely the £12 switch has broken, and needs replacing. It's a bugger of a job, and can be done from underneath the vehicle (did mine this way) the switch is p/no PRC2911, and just unscrews. It's located just behind the diff-lock stud above where the front prop fits.
Your options are thus:
1) Remove the front prop. Work blind and try and change it by feel alone. Helps if you can clean the area off before too, don't want any rubbish falling in the box! Unplug & Undo the switch, IIRC it's a 12mm head, and a stubby spanner is the tool for the job. Remove, swap the lower nut from the old switch to the new one (important for the length) and put back in. Don't do up too tight, or it may shear off (as my friend did 2 days after I did mine! He kept tightening it...) Pop the connections on and the front prop and the fault should go away. You could also just disconnect the switch if you want. IIRC open circuit is no-diff lock anyway, but if that's not correct then make up a link with some spade connectors and link it out then.
2) Remove the centre console, drill the rivets and attack from above. Same tools needed, just you can see what you're doing.
I favoured Option 1. YMMV!

SOURCE: 2000 landrover discovery td5 GS abs tc and hill

Suggests either Wheel Bearing, ABS Sensor Fault, or Shuttle valve. Best to get it to a dealer and on the computer for them to diagnose what exactly is wrong.

SOURCE: how to adjust rocker shaft on discovery td5

There are adjustment screws on the rockets according to RAVE.
The procedure is as follows:
1) Rotate the engine clockwise until No 1 injector lobe is at full lift.
2) Rotate rocker adjusting screw clockwise until the injector plunger is felt to bottom out.
3) Rotate rocket adjusting screw anti-clockwise one complete turn to give plunger the required bump clearance and tighten rocker arm adjusting screw locknut to 16Nm. Ensure the screw does not turn as the locknut is tightened.
4) Carry out the procedure for the remaining 4 rocker arms.
5) After completion of rocker arm adjustment slowly rotate engine clockwise 2 complete turns by hand to ensure that no injectors are bottoming out on their plungers.

SOURCE: landrover td5 abs light and traction control light

Sounds like a faulty Diff Lock switch to me.
Most of the D2 models till late 03 model year use a version of firmware on the SLABS ECU that when diff-lock is detected puts the ABS and Traction Control systems into a lower response mode. Late model vehicles came with factory fit diff-lock linkages as a option, and the firmware was revised to allow this to operate in conjunction with the traction control.
Therefore ABS and TC illuminating (but with no HDC) means your TC/ABS is in the lower performing mode, and your diff-lock may be in, but more likely the £12 switch has broken, and needs replacing. It's a bugger of a job, and can be done from underneath the vehicle (did mine this way) the switch is p/no PRC2911, and just unscrews. It's located just behind the diff-lock stud above where the front prop fits.
Your options are thus:
1) Remove the front prop. Work blind and try and change it by feel alone. Helps if you can clean the area off before too, don't want any rubbish falling in the box! Unplug & Undo the switch, IIRC it's a 12mm head, and a stubby spanner is the tool for the job. Remove, swap the lower nut from the old switch to the new one (important for the length) and put back in. Don't do up too tight, or it may shear off (as my friend did 2 days after I did mine! He kept tightening it...) Pop the connections on and the front prop and the fault should go away. You could also just disconnect the switch if you want. IIRC open circuit is no-diff lock anyway, but if that's not correct then make up a link with some spade connectors and link it out then.
2) Remove the centre console, drill the rivets and attack from above. Same tools needed, just you can see what you're doing.
I favoured Option 1. YMMV!

Your whirring noise and loss of power may indicate the diff-lock is engaging occasionally and may indicate damage to the transfer box.

SOURCE: Landrover Discovery TD5, ABS wan rning light

Hi:
The most likely cause of the ABS light coming on is a faulty wheel speed sensor. Your vehicle will still drive normally, but your ABS light means you don't have Anti Lock Brakes functioning. An easy way to figure out what is going on is to have an auto parts store download the codes on your vehicle, and they can tell you what tripped the ABS light, and you can go from there.

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