RangeRovers.net Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
Hi,

Just wondering if anyone knows the best course of investigation to take when encountering 'headlight levellling ecu not responding' and, if associated, 'light check module. dimmer potentiometer open circuit' faults.

I previously came across this when clearing a suspension inactive fault using autologic at a friendly garage, and see that neither will clear.

I do have an issue with the headlights not levelling correctly, with them pointing up into the sky, and with one periodically dipping right down before bouncing back up, for which the car failed its MOT yesterday.

Autologic are saying replace the auto levelling ecu (YWC000910), and that it is a known issue with moisture getting into it, but LR Stealers aren't aware of it being a known issue, and cannot find any other references apart from my similar thread on the LRO forum.

The major problem with this though, apart from the cost, is that its a main dealer part that's on back order. I can't find anyone, even breakers, who might have one! All the time I have an MOT failed car I can't drive just cos the lights point up a bit! I'm also not wholly convinced that after the wait it might necessarily resolve the issue.

Having googled these error messages there doesn't appear to be much, if any, information regarding possible causes. I do sometimes get a sidelight fault on front o/s, but see its ok bulb and connector wise.

Anyone come across this situation before?

Any ideas gratefully recieved!

thanks

Richard.
 

·
Registered
2006-2009 Range Rover MkIII / L322
Joined
·
99 Posts
Re: Self Levelling Headlights pointing up too much -- failed MOT

I'm not sure which year RR you are dealing with, but my '06 with adapative headlights had an issue with one pointing too high. I found that while the alignment is electronically controlled, they can still be adjusted manually with an allen key or screw driver, I forget which. This may align it enough to pass your MOT and give you time to source a new ecu.
 

·
Registered
Joined
·
1,423 Posts
Re: Self Levelling Headlights pointing up too much -- failed MOT

Another possible cause could be that the control linkage has popped out of the socket.
If you grab the back of the headlight assembly, where the light attaches into the assembly, see if it feels loose, allowing you to EASILY move it around a little, or if it's secure. Don't try to force it, you could pull the linkage out of the socket.
But if it does move about pretty easily, you could probably re-insert the ball of the linkage into the socket.
But to re-attach the linkage, I'm pretty sure you'll have to remove the headlight assembly.

Mine was loose and flopped around when I first bought it (used). I didn't think much of it, but noticed it didn't move the same as the other headlight did when they started-up, and that the rear of the headlight seemed really loose. And it was. Easily fixed when I removed the headlight to replace the ignitor.
Good luck.

And.... WELCOME TO THE FORUM, RICHARD!!!!:dance:


Visit often, and search as best you can for info before asking, to save yourself from bruising criticism and potential painful barbs, and to get better responses. And if you want usefull info, provide more info like what model year your RR is and where you're located.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #4
Re: Self Levelling Headlights pointing up too much -- failed MOT

Thanks guys for the thoughts and welcome, I'll check RAVE and see if either if 03rangiemark's idea could be a cause, along with possibility of getting it through the MOT by manually altering it down. Btw, it is a 2002 TD6 model and I am based in Surrey, UK.

cheers
 

·
Registered
2002-2005 Range Rover MkIII / L322
Joined
·
228 Posts
Re: Self Levelling Headlights pointing up too much -- failed MOT

The leveling headlights take their leveling information from the two right hand suspension height sensors. These hall effect sensors are quite robust, but as you have both a suspension fault and a headlight leveling fault I would suggest you start looking at all of these sensors. There are one on each corner, the two left ones feed only the EAS ECU, and the two right ones feed EAS ECU and headlight system. Get under the car and check all the connectors to all four, paying particular attention to the right hand ones.

I am away at present, and as such do not have access to RAVE or other documentation. Take a look and revert back with any findings.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
Re: Self Levelling Headlights pointing up too much -- failed MOT

Thanks for the feedback.

Both the front ride height sensors were replaced by me a few months back, as part of an investigation into why the front left seemed to be too low when driving, having had a split airbag and both front units replaced with new OEM Delphi units from island4x4. (http://www.lro.com/forum3/viewtopic.php?f=67&t=78739&sid=d532e6d53ffb6ff66fabc29e887211c7), and where the sensor was showing on autologic as being lower than the other corners on flat ground.

We'd already replaced the front crosslink valve at the suggestion of autologic, but that made no difference, so I thought for the sake of another £45 I might as well replace them, rather than get told to do so and charged 4 times as much by Hunters or Guava!
This still didn't sort the dippy suspension so had it down Guava's, who said the front left sensor was knackered. Not entirely sure I believed them, but they had to replace it under warranty anyway. Their technician was happy with the way they were installed, not that its difficult, being a 20min job to do both sides. That said, I did have to correct his knowledge of the suspension layout, as he was confusing it with that of a Disco3; not a good instiller of confidence for the £120/hr rate they charge! On the invoice it mentions they recalibrated the lights, and it seems to have started since then, however due to summer evenings I didn't notice until months later.

The new sensors do only have 3 pins in them though, rather than the original's 6. However, having queried this many times with Land Rover I have been assured that they are a direct replacement, so this can't be an issue. I even got them to find the paragraph in a doc that specifically said so!

I then wondered whether the light issue might relate to the fact that the EAS compressor was clearly worn, struggling to get up to 11 bar in a timely manner. The car was getting seriously 'bouncy' due to lack of pressure, so wondered whether the levelling ecu was just throwing a wobbly because of this; so didn't do anything about it because of the lack of night driving. I replaced the compressor last weekend and ride height is now perfect, but no change to the lights.

I'll get current garage to double check the offside height sensor connections though, just incase its got loose for whatever reason since fitting. It shouldn't have, due to the locking tabs, but then car does go up rough tracks regularly.
I believe they (Challenger 4x4 in Tongham) are currently in the process of swapping the ecu with one from another customer's car, who has apparently kindly let them do so, to check whether it really is the ecu before we wait, and are carless, for however long Land Rover might take to provide the part.

Having done virtually all the work on previous Land Rovers (1991 3.9 Classic, 1994 4.6 P38, 2001 4.0 Disco 2), I just wish I had the time to be able to do likewise with this car, rather than rely on garages! That said, Challenger are one I trust to do a good job and not to bullsh*t me.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #7
Re: Self Levelling Headlights pointing up too much -- failed MOT

Current situation now is that the auto levelling unit (YWC000910) has been proved to be ok, having swapped one from another car and also testing it in the other car. This now points to the LCM (YWC000540) which is, conviently, twice the price! I know you have to program the module because it stores VIN, mileage, service, etc, information in case of instrument panel failure, but can't find any reference to whether they are re-programmable if bought off ebay or from a breakers at considerably less cost.

Does anyone know if they are?
 
1 - 7 of 7 Posts
Top