One of the strong features of the LR3 platform is the fact that the underlying software supports numerous functions that can be activated when the necessary components are installed, including functions that were not available features on the LR3. In other posts I've written about my installation of the OEM electronic locking differential, which was an available feature for the LR3.

Radar-based adaptive cruise control (ACC) with forward alert (think collision warning without autonomous braking) was an option on various Jaguar and Land Rover models (Range Rover Sport to be specific) in the 2005+ timeframe, but not on the LR3 / Discovery 3. Some later year LR3s however do appear to have at least portions of the necessary wiring harnesses, and LR3s do have the software capability to support ACC with the right hardware components and edits to the car configuration file (CCF).

This retrofit is well documented on the Disco3 forum here. Given how well it is covered on that forum, I will not go through the full step by step process, but the parts I acquired were:

• radar sensor
• radar sensor connector
• control module with pigtail
• range rover sport steering wheel switches (you need the left distance toggle switch)
• center column hazard switch panel with forward alert switch (some write-ups indicate this is optional)

On the Range Rover Sport, the radar sensor mounts behind the bumper off center (on the US driver's side). I have an ARB bumper, and so I drilled and tapped 3 M8 holes for bolts and attached the sensor to the front of the ARB bumper.

While the OEM location of the control module is in the forward passenger cabin, I could not find a good mounting location and so I installed it in the rear cargo area which provided easy access for me to ground and CAN high sources.

The steering wheel switch install required removing the air bag which requires a special tool. The tool I ordered was too big, and so I ended up cutting the end off an inexpensive L hook (the kind you get in a $10 pick and hook kit from autozone or similar store) and that worked great. I had indications that my clock spring was on the way out and so I took the opportunity to swap in a new clock spring. In all, the clock spring replacement is not very difficult, just remember to have the battery disconnected before removing the air bag.

Three entries in the CFF are required:

1. speed control --> change this to Adaptive Cruise Control, from 'Speed control is fitted'
2. standard speed control display type --> change to "Adaptive speed control display type"
3. adaptive cruise control indication in instrument cluster --> mark as "Enabled"

From a pricing perspective, I acquired all parts from eBay in the UK and Europe with the exception of the sensor connector which was an AliExpress purchase. I would search first for parts on the UK eBay site; pricing in UK/Europe even with shipping was hundreds less than what is listed at US junkyards. E.g., you can find the radar sensors in the US for ~ $250, but from the UK mine was under $100 with shipping. A US-vendor asked for $400 shipped for the control module with pigtail, but I got one from Europe for $80 shipped.

Here's what the instrument cluster looks like when in use on the highway, as well pictures of the module and sensor installed:

 

Nice!! This is a mod I was interested in doing when I first got my LR3. But at the time I dont think anyone had done it. I love projects like this. Maybe this will be next on my list. Does not seem hard, about as hard as fitting a heated steering wheel to my 1992 750iL. You mentioned laters years may have some of the necessary wiring? Mine is an 06... so I winder what I may be missing. Again, maybe not an issue since I can and have built entire engine harnesses from scratch. I just dont want a fun project to become a headache. Will go browse that Disco3 thread now as it may answer some of my concerns.

How well does it work?

 

This is pretty cool....any idea what MY or VIN range the host LR3 would have to be within, in order to do this?

 

I only tested it for short runs getting holiday groceries today, but so far so good. It identifies cars and slows me down as I approach them. In city driving, I drove with the 'forward alert' switch depressed and it did beep at me once and flashed a 'Driver Intervene' message on the instrument cluster when it thought I was closing too fast.

As for the partial engine harness, there's a nearby thread in this section (I posted to it a few days ago) that asks about a mysterious yellow connector in the US driver's side footwell. That yellow connector is the ACC control module connector. Page 16 of that Disco3 thread has excellent wiring diagrams by the way, and I found it easy to assemble my own harness. There are two relevant connectors: 1. the control module connector, and 2. the radar sensor connector. With those, the remaining harnesses can be built relatively quickly.

After this, my next retrofit will be the blind spot monitoring system from a later year LR4, though this will be a bit trickier of an install because the mirror connectors are not interchangeable between the LR3 and LR4.

 

I know I read that a bunch of '06s had done this on the Disco3 forum and it's possible an '05 was mentioned but I don't recall. Mine is an '06. Surprisingly it appears that there are a few years of the LR4 where this cannot be retrofit.

 

Not sure how the blind spot system works on the LR4, but if it taps into the CAN bus, you are out of luck. If not, no worries. Although you may already know this.

edit: Another weird project I wanted to do some while ago is the folding mirrors. Really easy to wire in, just need motorized mirrors. They stand out because they have two harnesses coming out instead of one. I dont think the US market had them though, so have to buy from UK or such.

 

The parts of the LR4 2016 blind spot monitoring system consist of:

• BSM enabled mirrors (which is also a power folding mirror, though the internal mirror connection needs to be rewired slightly to work on an LR3)
• left and right sensors, which each have their own integrated control modules

There are 8 wires going into the sensor assembly from the car (there are also 2 private CAN lines between the sensors, but these do not branch out into the car):

• "alert" and "status" wires, one pair each for each side (so this is 4 wires)
• battery power
• ground
• medium speed CAN low
• medium speed CAN high

I suspect the medium speed CAN wires are to grab the status of the turn signals. While installing this may not work, I am given some confidence by the fact that the CCF for the '06 LR3 does have a value to enable to tell the car the system is present (it shows up in the CCF as "side object detection").

Work or fail, I will know in a week or two and will post a separate thread.

 

The concern is CAN bus to the LR3, the LR4 uses a different bit rate. So any module for an LR4 that uses the CAN bus will not work on the LR3 CAN bus. Worth a try though, maybe there is some voodoo in some systems that can detect and use the correct bit-rates. But my extensive poking around with the LR4 nav display and audio system indicate this is not the case normally.

How did the system function? Did it only enable with the blinkers turned on? If so, then maybe you can do some funky wiring with a relay to power on the module with the blinker. But my concern is that if the CAN bus does not work, the model may not even activate without a handshake and login to the bus.

 

How have i not seen this before, would making using the CC worthwhile instead of constantly having to account for drivers that cant maintain a consistent speed.
Better start looking for those parts.

 

Being that I have an 06, I was hopeful I had the connector but figured I did not. Sadly I looked and do not believe I have the yellow connector referenced here:
https://landroverforums.com/forum/lr...ng-plug-70066/




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