2014 D4 in Limp Mode

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Originally Posted by SBD4

U0001-88

• High Speed CAN Communication Bus - Bus off
• Bus off
• Refer to the electrical circuit diagrams and check the power and ground connections to the module. Using the manufacturer approved diagnostic system, complete a CAN network integrity test. Refer to the electrical circuit diagrams and check the CAN network

U0100-00

• Lost Communication With ECM/PCM "A" No sub type information
• No sub type information
• Refer to the electrical circuit diagrams and check the power and ground connections to the module. Using the manufacturer approved diagnostic system, complete a CAN network integrity test. Refer to the electrical circuit diagrams and check the CAN network between the engine control module and traction control module

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From the WSM...

'Bus off' DTCs
The references to bus and its condition refer to the network concerned and the modules on that network.
If a module logs a 'Bus Off' DTC, it means that the module has detected CAN transmission errors and has disabled its's
own CAN transmissions and disconnected itself from the network in an attempt to allow the rest of the network to
function. At this point the 'Bus Off' DTC is set. A common cause of 'Bus Off' DTCs can be a short circuit in the CAN
network.

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Originally Posted by Bradmc

Main battery terminals are tight. I will check behind drivers kick plate as you mentioned.

My DBS was earthed on the body in the engine compartment. I have totally removed the DBS; so that is a non issue now.

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Noting Graeme's post, did all wiring looms around and potentially under the aux battery tray look ok? Any abrasion? I think you said no rear a/c so not like Mungus. If not happening near battery then it may be difficult to trace. Any other areas been worked on?

Scott

I don't have rear aircon or electric trailer brake controller.

I have removed the whole DBS, and the wiring around that area looks fine. I have disconnected the winch. The only other accessory I have is spot light; don't believe that to be an issue as the wiring looks fine. Note: I've had all these accessories on the car for over 8 months.

I did change the rear pads two months back, and brake warning wire looks fine, I would not think that would cause the issue I am having anyway.

I will have a wiggle of the wires today. The car went into full limp mode yesterday evening, so it would not start until after I disconnected the battery; although engine light remains in fault. I am predicting I will be clear this morning.

I live in the inner-west of Sydney btw.

From what you have posted, I don't think the DBS itself is the problem, as others have posted, the problem may be a result of the way the DBS was installed.

BUT, I think Graeme is probably on the right track and you may have some wiring that has rubbed through somewhere and is causing a temporary short.

Unfortunately, this is a common fault with LR's manufacturing "skills"

There are plenty of reports of this type on problem occurring in the UK and the USA and here as well.

This one is one you will most likely have to sort out with the dealer.

I had something similar where the suspension in my 07 RR never worked from the day I drove it out of the showroom, and no matter how many times I raised the problem, neither the dealership or LRA gave a hoot.

I eventually found the problem, a deformed wire loom connector and my $170.000 RR's suspension was finally working thanks to a 10c cable tie.

Do as much detective work you can do yourself, and then take it up with the dealer.

BTW, one of the more common problems is the wire loom being crushed near the driver's seat, when they fix the driver's seat in place.

You stated you checked the tailgate and this seam to fix the problem.

I wonder if you actually getting out of your seat, to check the tailgate, was "fixing" the problem.

Car is now in normal mode as predicted. Had my wife sit in the car whilst I wiggled all the wiring looms and connections I could find, even under the car.

Checked the wiring beside drivers foot well, all seemed OK.

I have ruled out the tailgate as a problem as I've tested the theory many times now.

The issue is beyond my level of knowledge now, so off to LR on Monday. I'll let you all know how I get on.

So you've already removed the aftermarket gear & it's under warranty - off to the dealer - I'd take them for a drive through somewhere where you know it happens so you can show the dealer first hand it occurring - otherwise you might get an "unable to replicate fault" response - loan car until they fix it.

Just reading the ABS fault codes should provide a good starting place to look.

Are you using an OBDII diagnostic unit? I had some canbus problems when an OBDii reader used a conflicting protocol on the CanBus. It was a Bluetooth OBDII reader from a well known manufacturer though not specific for LandRover.

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Originally Posted by RoverLander

Are you using an OBDII diagnostic unit? I had some canbus problems when an OBDii reader used a conflicting protocol on the CanBus. It was a Bluetooth OBDII reader from a well known manufacturer though not specific for LandRover.

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Incase you are unaware,these vehicles run a second canbus system,it doesnt meet international protocols,could explain why your OBDII reader has problems talking to the Land Rover.
Andrew