[alexplank]

This is a 2003 Range Rover L322.

I cannot get my high beams to work. I've even replaced the LCM & the entire turn signal stalk.


The lights won't come on even if I set the full high beam or dim high beam daylight running modes on the LCM using RSW so I don't think it's a switch issue. Dip daylight running mode works as that uses the low beam xenons obviously.


Anyone have any thoughts? I can't connect to the RH xenon ECU/igniter with any diagnostic tools so I thought that could be causing some error in the system, but I disconnected it and the high beam on the responsive light doesn't work even with the non-responsive headlight unit disconnected.

Both of the xenons work fine on low beam mode.

I plugged a BMW scanner into the OBD port to see what the LCM sees and I notice that the switches for the high beams are yellow even when they're on. The program says the high beams are on when daylight running mode with high beams is enabled but it doesn't say they're on when the switch is pressed forward or flashed.

Interestingly RSW All Comms cannot read LCM faults (it just won't connect under the read faults section) even though it can reprogram options on the LCM. It won't connect for fault reading with the old LCM or the new one I installed. My other diagnostic tools can read LCM faults though (the icarsoft 930i and the bmw scanner)

 

[Mrmerlin]

remove the hi beam bulbs and check them

 

[alexplank]

remove the hi beam bulbs and check them

As much as I'd like that to be the issue, the bulbs are fine. I should have mentioned that the bulbs were replaced before trying more drastic measures. A test light does not light on the connector either.

Here's what happens when you start the car with the dip beams on and one high beam unplugged (headlight dial set to on position):

here's what happens when the lights are set to off but daylight running mode is enabled for high beams as well as dimmed beam with daylight running mode (and one high beam is unplugged. notice the car doesn't notice the unplugged high beam here):

Here's what happens when just DRL is checked:

 

[Mrmerlin]

what was the last thing that was worked on before this issue started, dead battery or alternator fail or anything else?

 

[alexplank]

what was the last thing that was worked on before this issue started, dead battery or alternator fail or anything else?

I don't know as it's been like this since I got the vehicle.

I want to test the pin that comes from the high beam switch on the steering wheel but the connector in the middle of the LCM seems to be hard to test. There are over 50 pins and it seals when connected with no way to touch any metal unlike the other connectors where you can just stick a lead on the top of the connector for the pin you want to test.