Hi Guys... Sorry for the long post. Its time to kick off my winter project (2005 Lr3 with 72,000 miles). I’ve posted a few things on the forum over the months before I did my proper homework and bought the IId Tool. So now I’m more educated, have codes, I'm and ready to ask the right questions. I bought the project LR3 because it came out of Arizona and is clean as a whistle. It literally looks brand new. 72,000 miles and spotless Interior and Exterior. But she has electrical issues and had water in the Driver footwell and Driver floor sill where all the wires pass. The Driver A Pillar Roof drain was split (as is common) and was dumping rainwater on the floor. That is now fixed and all dried up. No signs of wire corrosion on the Driver Floor sill or A Pillar

She Cranks and idles fine. Will shift forward and reverse and move slowly under her own power... but feels like limp mode or stuck a higher gear... Dash is lit like a Xmas tree. Parking Brake light, HDC light, Traction light, Check Engine light, Suspension lowered, Trans Fault message, and all gears not available message. Something is causing a failure someone along the HighSpeed CANBUS. No way all these things failed at the same time. I’m trying to find root cause

I’ve spent endless hours on the Forum and learned a ton. I have the IId Tool and pulled the codes:

U0122-87 is present in the Airbag, Parking Brake, Steering Angle, Suspension, and Terrain Control ECU
(LOST COMMUNICATION WITH VEHICLE DYNAMIC CONTROL MODULE or as I call it the ABS Module)
U0122-00 is in the Engine ECU (LOST COMMUNICATION WITH VEHICLE DYNAMIC CONTROL MODULE)
U0416-86 is in the transmission ECU (INVALID MESSAGE FROM VEHICLE DYNAMIC CONTROL MODULE)
P0504-29 is in the Engine ECU (BRAKE SWITCH A/B CORRELATION)

After hours on the Forum I started with the Obvious potential causes and none have made a difference.
After each change I tried to reset the codes with the IID Tool... But the codes remained. Same problems exist.

1) Checked for the famous red wire splice in the Passenger floor sill (1 into 2). Wire was fine. Checked splices in both Floor sills.. All look good and no corrosion.
2) Replaced Tail Lights with OEM Land Rover bulbs... no difference... Disconnected Tail and Headlights.. No difference...
3) Brake Switch... changed with new unit and no difference... Changed again with another new unit in case I screwed it up 1st time... no diff
4) Replaced battery and checked charging system.. 12.6 volts sitting... 14.6 running.. all looks good
5) Checked all fuses (under hood and behind Glovebox)... pulled and reseated... seats feel good. No loose wires visible and no corrosion visible
6) I had a spare ATS module (the 1 behind the battery) so I swapped out... no difference... But now also get the VIN ID Mismatch error in the ATS ECU (as expected).
7) Pulled the center console and checked all the connections for corrosion. Clean as hell under there. looks brand new.
8) Since water was leaking down the A Pillar I thought maybe bad connected at the Air Suspension Control Module. Checked Harness connection. Looked good.
Tried cranking without the Module but won't turn over without that module plugged in. Replugged Harness and moved on

So now its time to go deeper.

I have a few areas I suspect to go next. Where would you go next? Any suggestions?

1) Since most codes point to the VDCM (which is the ABS module)... Maybe I should bite the bullet and replace the ABS module (could also send off for Electric repair at upfix.com). With this many codes all pointing to the VDCM (ABS Module)

2) Also heard a bad Instrument Cluster could cause these issues. Perhaps pull the cluster and check for bad connection at the harness?

3) Can I use the IID tool and its live value feature to better track down where the failure in the CANBUS is happening? Can I better identify where the issue is? Somewhere along the CANBUS wiring there is either a break or 1 of the ECU is actually bad and sending a bad signal to the others. How can I track that down? Any thoughts?

4) I've read on here that some people try disconnecting ECU, turning key on, and trying to reset codes. Anyone try that to see if they can find a bad ECU somewhere?

Thanks a ton guys... I look forward to your thoughts. This LR3 is WAY too nice not to fight for and try and find the issue.

BTW... I/m in Milwaukee

 

Try checking the battery ground cable, they look good but won't carry enough current, and there is a ground lug behind the right front inner fender that can cause issues

Hope this helps

Jeff

 

Hi... thanks... I was tinkering today with the LR3 and tried a few different things. Question... when you say Ground lug behind the passenger fender well...
do you mean the 1 that directly connects to the negative side of the battery and is about 12 inches long? You can see that 1 with a flashlight behind the fuse box as it
ties into the inside of the inner fender well.

Colby

 

There are 2 more ground lugs behind the passenger/right fender liner - separate from the negative battery ground right behind the battery. One comes from the motor to chassis ground cable and the other, higher up, grounds several other lines.

 

Hi... thanks again for your help. I assume the inner fender liner needs to be removed from under the wheel well to get to those ground lugs?

 

That's right - it needs to come off to get to those lugs. Make sure to get some spare plastic push in connectors to re-attach the liner before you take it off. Some generic ones in an assortment pack from Amazon worked for me. One size in this item will work:
GOOACC GRC-30 120PCS Car Retainer 6.3mm 8mm 9mm 10mm Expansion Screws Replacement Kit Bumper Push Rivet Clips, 1PC Fastener Remover https://smile.amazon.com/dp/B07FV5ZJ...ing=UTF8&psc=1
Oh and by the way the engine to chassis ground ran to 2 different lugs maybe 8 inches or so apart from each other on my 08 4.4L when I did this recently. I also managed to clean up the lug on the engine, but you kind of need a double jointed arm to reach in there to do it. Make sure your battery is disconnected, the suspension fuses are pulled out (just to be extra safe), and the vehicle is resting on a jack stand or two before you put your arm through there!

 

Did you ever resolve your problem? Electrical problems seem to be part of the magic of Land Rover ownership, not meaning to be nasty, just curious...
I have gone through the same hair-pulling electrical issues, likely with many others on this site...

 

All the comments about electrical grounding are valid, plus I used GM fender liner push connectors, they were cheaper and seemed to work well, keep investigating basic electrical issues and good luck!

 

By the way, this post has some great info and pics to guide you in checking out and cleaning up the grounds. Don't forget to use some dielectric grease when re-asembling:
https://landroverforums.com/forum/lr...roblem-108590/

 

Fantastic... thanks much!