I recently bought a used 2005 LR3 v8 SE 4.4 with 99,500 miles. When I first picked it up, the car started and ran well. Then I started having starting issues, where rig would start, would run fine, then not start after it was turned off with multiple warnings on my dash including the giant F off to the side. When I left the car overnight it would again start in the morning and run fine, then not start after it was driven for a while. Obviously, something electrical was wrong - something LR3's I know they are know for. I have read about similar LR3 problems but so far those solutions have not worked. So far I have done the following, but the problem persists:

1 ) Sun Roof Drain Issues - When first I picked up the car I notice there was water in the passenger side floor which I cleaned up. When it began having starting issues, I did some research I found was the water caused by a faulty sunroof drain line, which I fixed (drains properly now). Checked out the wiring underneath the wet carpet - did seem to be any corroded wires or connections.
2) Transfer Case Control Module Replaced - I also found out the water intrusion can cause problems with the Transfer Case Control Module (TCM). Thinking that this may be the cause of the starting/multiple warning light issues, I replaced the TCM with a new one and cleaned up the electrical connectors. The hot non-start/warning light issues continued.
3) Air to Coil Spring Suspension Converted - During this time the were issues with the Air-Suspension, which I though may be contributing the to the electrical issues. So I purchased and replaced the Air Suspension with the Coil Spring Replacement Kit from Atlantic British. The new Coil Spring System worked fine and there was no more ride lowering/raising issues, but the car starting issues continued.
4) Brake Light Switch Replaced - Found out the Brake Light Switch can cause problems - Replaced and brake light work fine.
5) Starter Replaced - Then I was told the problem was likely the starter, so I replaced the starter (a pain in the *** to do). The car started fine after installation, no warning lights.But, again the same hot-no start issues.
4) Checked the alternator - charging @ 14.5 volts does not seem to be the problem
5) Replaced battery - was battery (dated 11/2023) and seemed to be good - 12.5 volts. But replaced it with a better battery anyway.

Now that I replaced the battery the car will not start even when cold, I still hear clicking behind the dash when I turn the key, but engine does not crank.
And the followingWarning Lights continue to appear:
-BRAKE: Amber Color
-PARK BRAKE: Amber Color
-PARK BREAK: Red (actually working, stays on unless I disengage)
-DSC: AMBER (clicking the button has no effect) and continually stays on

MESSAGE CENTER:
-PARK BREAK FAULT
-HDC FAULT SYSTEM NOT AVAILABLE
-ENGINE SYSTEM FAULT
-TRANSMISSION FAULT (Not all gears available or something)
and more about the parking brake.

Other Solutions I've tried.
-Checking taillights: all illuminate and are very bright
-Checked fuses: I checked the fuses related to the starter, ECM and TCM under the hood and inside the passenger compartment and none found were bad.
-Disconnected the battery, connected the two ends for 15 min to try a hard reset and then put it all back together. (turned on with all lights still illuminated)
-Checked for loose or disconnected wires - none found.
- Connected Code Reader and erase codes - still getting "Loss Communication with ECM/PCM-A" code.

It looks like some sort of ECM or PCM or BCM issue?a - but that is just a guess. Would appreciate any input or clue as what the culprit could be?
Thanks!

 

I suggest buying a GAP tool and reading the codes.

 

+1 on the GAP tool. The ~$400 price comes as a shock, but it's worth every penny.

 

You've probably replaced parts that weren't required and ruined the vehicles excellent ride with the coil conversion which didn't even fix the issue, was the TCCM programmed to the vehicle as they aren't plug n play.
Apart from having the codes read you need to check all the earth points and any electrical connector,

 

Thanks for the response.
New TCCM was not programed to the vehicle, but did start after it was installed. Have checked the earth (ground points)
I suppose I have to take it to Land Rover Dealer to have it programmed. Problem with that is the closest dealer is 260 miles away.

 

Reach out to GAP IID customer support (https://www.gap-diagnostic.com/support/contact/) and see if the GAP tool can program the TCCM. They may be able to send you the necessary firmware via download to the GAP tool (so you'll need to buy one) directly, and you only need a smartphone to use the GAP tool. It gives incredible access to various LR3 systems. For example, I used it to reflash the firmware on a rear differential electronic control module.

 

OK - Will check the GAP out.
I appreciate the help. Will let you know how it goes.

 

They certainly can, you purchase a fastlane flash and they include it in a firmware update.

 

Thanks for the info -
Just purchased the GAP IID Tool BT (G3) and the Fast Lane Service. Hope it leads to a fix.
All I am getting from my current code reader is Code U0100 -Lost Communications with engine control module/power train control/module A.
Is there a reason that would cause this message?
Or could it be caused by the new TCCM not being programmed?
I am a novice with this stuff, but don't mind learning.

 

Lost comm is nothing