Hello All,

I have recently replaced my CATS suspension on my 2005 XJR with a stock S-Type set up. Car rides and handle great and no light in the dash after unplugging the ASCM and doing a hard reset.

I now have no auto leveling for the headlamps which I expected. I see from the wiring diagram, there is a single yellow wire going to the Headlamps , The diagram describes the signal as output,. Does anyone know what the output signal is? Voltage? 12 Volts or lower. It looks as if one could bypass the module and connect a ride height sensor direct to headlights to restore the auto leveling feature.

Has any one done this or is there another way to get the headlamps up?

Wooford XJR

 

Someone damaged/disconnected the suspension ride height sensor during repair?

Check all 3 suspension sensors and you will likely find the fault. (right front was deleted from G26872 onward)

If you disabled the ASM then you will not be able to use the auto-leveling. (No Communication)

 

Self-levelling headlamp units were only fitted up to chassis number G39154. After that headlamp levelling was acheived simply by the self-levelling air suspension so if your VIN is G39155+ then you've lost all self-levelling of headlamp beams

The reason that the 350 originally had self-levelling headlamps was that they were initially specified (before production started) when it was originally intended that air suspension should only be a high-end option and that the standard option would be conventional spring suspension. In the event the standard option never happened and from the outset all cars had the air suspension so the self-levelling headlamps were deleted, presumably when the original stock ran out.

 

Thank you both Motorcarman and Patrick the Cat for you replies

My Vin # is 35910. If you look at the wiring diagram Fig 5.3 shows one single yellow wire at terminal # CR89-3 out of the ASM that leads to Fig 8.6 which is wiring diagram for the headlights and the wire leads to terminal ECS15 which splits off to each headlight. It is providing some type of input to the headlights, I am asking what the input is?

Woofod Jag

 

Well, if it's from the air suspension module it would seem to be the signal to tell the levelling motor how much to lower the beam. I can't see what else it could be.

However, as you say you've disconnected the ASM then it can't be generating a levelling signal so the headlamps won't move; in the absence of a signal they may well simply move to one of the extreme positions and stay put.

EDIT: apparently the signal on that yellow wire is pulse width modulated - which is not the type of signal from the height sensors (they are analog voltage signals) so there's no way you can connect the height sensors directly to the stepping motors in the lamp.

 

The reason for the 'leveling' is to prevent the (very bright HID) lights from blinding oncoming traffic (or aimed at the ground) and keep the beams optimal when the weight in the boot or passenger compartment alters the headlamp aim. (even an airspring failure can change the headlamp aim)

The car is an integrated system. You change one thing and it affects other systems. You have disabled one of the inputs.

Replacing a headlamp assy. requires the system to be reconfigured. I reconfigure headlamps after people get a front end damage repair from a body shop, most don't have the equipment to make all the network modules 'shake-hands'.

Franken-cars can get some things the way you want but might have unintended consequences.

 

Motorcarman,

Thank you for your response. I understand the headlight leveling helps compensate for passenger and trunk (Boot) loads in order to keep them from being to high or low. When I hit the headlight button on my key fob, the headlights come on and raise up. The wiring diagram has one wire going to the headlights so I have to assume it has something to do with the headlights adjusting up and down. I want to figure out if there is a way to replicate the input signal and adjust the headlights via another means other than the ASM.

Wooford Jag

 

I know my car is a base model not an "R" (my 2004 serial # is G07332) but I replaced my air suspension with the Arnott strut kit in July and noticed that it retained the leveling action for the headlights. Every morning I see the headlights rise against the wall when I start the engine.
I did use the module supplied by Arnott placed under the rear seat. I don't know if the module has any interface with the circuitry related to the headlights or not. I will try and find the instructions as to the wires that were used by the module, it may prove useful to this thread. As a side note while the kit does do what it is supposed to I may one day return it to the air struts as the coil is not as responsive as I had expected. However I do not have to worry about the leaking strut again.

 

Some very interesting info appeared here already but I fear some of you guys out there have been confused as to what I require.
I don't want the headlights to be sent a signal (on a yellow? cable).
My Jag had originally the levelling headlamps.
The Euro lamps do not.
I need the ASM NOT to be wanting to send a signal.
Or to find some way to send a dummy signal back to the ASM that all is OK.
As I explained at the beginning the UK spec wiring harness has 9 cables but the Euro spec lamp unit only 6 contacts.
Therefore 3 are not being used anymore as there are no levelling mechanisms in the Euro lamps.

The car is.......
2003 XJ6 3Litre V6
VIN GO6864

 

very late but i think you can flash the asm as a halogen in ids