ABS/HDC/SL Warnings all on

My 99 Disco TD5 has intermittently had "jackpot" dashboard syndrome for 4 years now. ABS/Brake Fail/HDC/Self Levelling etc. all on. In that time it's had a new ABS modulator (£1000) a SLABS ECU (Warranty) and about £600's worth of out of Warranty labour charges. The problem only seems to happen when the weather starts to become colder and damp - usually about late Sept/Oct. Various suggestions have been made regarding the under bonnet fusebox (swapped with an identical one - no cure), the wheel sensors (all check OK on Testbook) and the Battery (replaced). Testbook 4 always indicates the ABS modulator is at fault, but of course it isn't. Any suggestions?

Sounds like Brake sensors to me, i had same thing, ABS, TC, HDC, Sensor had come unclipped and was wearing away on drive shaft. Thats all I can think of

I have spent loads of time on abs on disco 2, 1 common fault is the earth above the glove box where the slabs is located its a single black wire on its own and this is a main earth point for slabs not allways shown on wiring diagrams and often overlooked,the other thing is that a overlay harness was fitted on problem cars or the connector was cut out in the inner wing and soldered toegether,the main point to check when slabs says no faults is to look into the slabs internal ecm data,and look for wheel speed sensor disturbances these are not reset every ignition cycle so can be read on t4 i had a problem car in 3 times till i cured it hope this helps tiga

Sorry to dig up this old thread.

I have just experienced the same problem.

The lights stay on and do not go off when the ignition is restarted. The ABS DOES work - surely that means the modulator and sensors are fine????

Where are the sensors located and can they only be checked by a dealer or is there some way I can test them?

The sensors are in the wheel hubs, and the ABS will still work if its only an intermittently dodgy sensor. Replacement sensors cost around £60, you'll probably need to use test book to find out which one (if any) is on the fritz.

Oh yeah and you'll defiantly need test book or autologic to turn the lights off even after you find and fix the problem

just behind the nearside headlamp, between the headlamp and air filter, you'll see 2 earth points, one of these is the earth for the abs modulator, I've seen these corroded and loose in the past causing the exact fault you describe. They may just be making contact when its dry but add a little water and the resistance increases.

Thanks - did check the 2 earth points last night - all seems fine.

I have booked her in to be checked out in 2 weeks time - lets see what they say.

After replacing sensor's and hub's a wharped brake disc fetched my lights back on again everytime the pads found a low spot so they were replaced with performance ones, the mechanic said next time they come on he'll be looking at the wheel bearings.