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Freelander ABS ECU brain surgery


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I realise that asking a Land Rover forum for diagnostics on the insides of a black box of electrickery is liable to get me burned as a witch, but I think I found the reason for my ABS, TC and HDC lights being on:


Basically, you're not supposed to be able to see the little houses and roads where the magic smoke people live... some ham-fisted previous owner/mechanic has smacked the ABS ECU with something and knocked the (sealed to prevent water ingress) cover off :rolleyes:

I've pulled the brains bit off, and bought it indoors to dry it out and give it a clean up with some pukka PCB cleaner. There were a few slightly corroded bits which could well have upset it, or it could be completely toast - I'll be plugging it in to find out at the next available opportunity, and if it works I'll lacquer the PCB and pot it and call it a bargain.

But, it would be nice to be able to bench-test the unit, if only 'cos my bench is warmer than the shed floor - so if anyone has a diagnostics manual or any info on testing it that would be greatly appreciated.

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Here are some 'remedies " from other forums. And some wiring diagrams that "might" help



The accelerometer is mounted beneath the centre console adjacent the handbrake, and provides the ABS ECU additional information regarding vehicle motion. The ABS ECU (C0500) provides a feed to the accelerometer (C1220) on a yellow wire. The sensor (C1220) returns a vehicle acceleration/deceleration signal to the ABS ECU (C0500) on a red wire. The accelerometer (C1220) is provided an earth path via the ABS ECU (C0500) on a blue wire.

Thanks Guy's for the info, I have now managed to sort it.

I think it was the brake switch under the foot pedal that had come loose abit.

I reseated the connections and secured it and now all lights have gone out. Done over 100mile and everythings seems to be ok.

many instances of the HDC/ABS/TC lights illumination are a failure of (yes the brake pedal switch) and the longitudinal acceleration sensor assy.this calculates the rate of 'G' when braking and is fundamental to the ABS ecu calculation.

costs about £60, is located on the floor pan to the rear of the handbrake assy, easily replaced

there is an enormous amount of info on the teves Mk 20 and Mk 25 systems that was never released to the general public regarding the ABS system on the freelander

the problems are:

upto 700 lines worth....

corrosion on the terminals at the ABS modulator, the block

pump voltage supply problems

brake pedal switch production faults

'g' sensor failures

ok ok ok

after supporting a
of garages & engineers..

don't panic, don't give up or sell out...

still a lot of motor for the money

people say freelander is simple and stupid but theres a lot more going on under the skin than you first see

if it's the g sensor it's an easy replacement but requires a diagnostic tool to calibrate.

don't be put off by anyone saying 'it's not eobd or compliant...bulls***

tell you what...

new brake pads..ok, i've only ever seen reset faults on the L322 after replacement...thats the new rangie

theres little to go wrong, and if it does the only sticky point as i said is the calibration.

the modulator, pads, brake pedal switch can all be replaced without diagnostics

if hte fault re-occurs, study why..

ok if it's a really early system...say 99 to 2001

it's a possible seperate ecu

this aint so good

its gonna require a replacement unit as per technical bulletin from LR


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I think you are unlikely to find any help there,a few places like Allcar electronics seem to do a reasonable job of testing and repair on engine ecu's.But I've never asked them about ABS ones.If it is stuffed then a replacement off E-Bay is probably the best way to go,I did one last week for a car sales outfit - quick job,undo the plug then 4 screws.

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