I've got a desire to make some mods to my lights, to make them operate a little like an emergency vehicle (hazard strobe, alternating headlights etc). Note, these will not be on-road use.

So my question is, can this be done with programming alone? If so, has anyone got any tips as a starting point? I know I can intercept the wiring to the lights and provide new signals, but would ideally like to add a module, perhaps to the ODB2 port which will do this as I feel shoving additional signals over the CAN bus might cause errors to be logged.

Something like this perhaps?  __
2018 L405 3.0 TDV6 Vogue SE Fuji White
2000 4.6 V8 HSE Oxford Blue
1994 3.9 V8 Vogue Ardennes Green - resto project

Land Rover History:
2010 3.6 TDV8 Autobiography Stornoway Grey
2001 Discovery 2 TD5 GS
1999 Discovery 2 V8i XS
1994 Discovery 300Tdi
1993 Discovery 200Tdi
1989 Range Rover Vogue SE 3.5EFi
1976 Series 3 2.25
1977 Range Rover 2 door 3.5 Carb

Sorry, only just seen this.
I have previously developed modules (hardware and software) and also CAN bus loggers for clients.


I've just checked the wiring diagrams for this area, and it is clear to see the 'Central Electronics Module' (CEM) is connected to the switches and the lights using traditional wiring. They aren't controlled using CAN messages, and it doesn't look like the CAN bus is connected to the headlights at all.
Whether you can issue a command to the CEL in order to control the lights, I have no idea.


I believe the OBD connector is directly connected to the CAN bus on the RR, so you could probably monitor the bus, but I'm not sure if that will help you. I haven't attempted to log anything off the RR, but don't see it as being an issue.

You may well find the companies that outfit cars for emergency services already have modules for this, but they will be spendy. Then again, they may well modify the wiring in order to insert their own modules between the CEM and lights.
This would certainly be the easier approach imo.

Happy to answer questions if I can help. Not sure how far you can get with simply plugging something into the OBD port though.

Cheers,
John. Too many toys, not enough time

2011 4.4 TDV8 AB Black

Thanks, I've just dropped you a PM. Hope that's OK... __
2018 L405 3.0 TDV6 Vogue SE Fuji White
2000 4.6 V8 HSE Oxford Blue
1994 3.9 V8 Vogue Ardennes Green - resto project

Land Rover History:
2010 3.6 TDV8 Autobiography Stornoway Grey
2001 Discovery 2 TD5 GS
1999 Discovery 2 V8i XS
1994 Discovery 300Tdi
1993 Discovery 200Tdi
1989 Range Rover Vogue SE 3.5EFi
1976 Series 3 2.25
1977 Range Rover 2 door 3.5 Carb

John a closely related question: I'd like to introduce a repeater volume control (for volume tweaks from the rear) was wondering if that would be possible? Either CAN or just repeating the switch in parallel?
.
.
. Cheers, Greg
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2011 Vogue SE 4.4 with lots of toys in Stornaway

I will reply to your pm in a moment

Greg, this will probably need to be a MOST module, not CAN bus.
Having taken the head unit apart, you could undoubtedly try to parallel up a volume control, but it would be messy as it's not a potentiometer, it's an optical encoder with an interface pcb. To make a module from scratch would be a lot of work.

I would work along the lines of using a remote and it's receiver module, or cordless headphones which have volume controls on them.

There are modules out there to interface to the MOST bus (mainly for phone and mp3 interfaces) but everything seems to be 200 up.
Send me a pm if you like, we can talk about it more. Too many toys, not enough time

2011 4.4 TDV8 AB Black

This sort of thing was/is possible with the 1st gen FFRR (BMW) using the BMW Android app. On could setup a sequence for all the lights .
Experience is the only genuine knowledge, but as time passes, I have forgotten more than I can remember
Volvo V70 P2 2006 2.4 Petrol 170bhp Estate SE
MG Midget Mk1 1962

Previous: L322 Range Rover TDV8 3.6 2008; L322 Range Rover TD6 3.0 2002; P38A Range Rover V8 1999

Ah I see John, does sound more complicated than my assumption.

But one thought - there is a repeater already - the steering wheel vol. control is a dual control.
I was going to order one of those, or the one I've seen in the rear of the Ultimate Edition.
Here it is in the WM:

I assume the steering controls go to a control module that interfaces to the amplifier module, so it is entirely possible you could insert another of these to inject the signals / can messages.
My concern would be how the BCM might cope with an unexpected duplicate module.
If they aren't too expensive it would be worth giving it a go

I've not dug through the manual to see how they link up. Too many toys, not enough time

2011 4.4 TDV8 AB Black

OK cheers John.
I'll study the WM a bit more to see where the steering wheel control goes to.
.  Cheers, Greg
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
2011 Vogue SE 4.4 with lots of toys in Stornaway