Discovery 4 electrics turn off while driving

[Steve86]

Hi All,

So we managed to get a month into disco ownership before an issue came up.

While driving we have a number of items intermittantly turning off & on including temp gauge, air con, central display unit, parking sensors, indicator display. Fortunately there's no mechanical shut-offs & speedo, lights, indicators (external) etc continue to operate. No warning messages until the car is switched off & a whole bunch flash up. It clears when the car starts up again.

Very similar issue reporting in this thread:
2012 LR4, electrical issue. Dash go blank while driving. - Land Rover Forums - Land Rover Enthusiast Forum (https://landroverforums.com/forum/lr4-38/2012-lr4-electrical-issue-dash-go-blank-while-driving-96794/)

Quote from thread:

So take your pick on what fixed mine:
1. New alternator, which was badly needed anyway
2. New BMS, which was also reset a few times
3. Refurbished instruments, but they had other issues anyway
4. New battery, the new battery I previously fitted was not holding charge properly, but that could have been caused by the electrical issues as I was getting some strange charging behaviour
The problems still persisted and became more frequent until:
5. I played with the wiring in the centre console ( lots of large connectors carrying the HS and MS can bus there and most of my faults related to the MS canbus)
One more instance of the faults, then nothing since.

Personally I suspect a dirty connector. It would work intermittently when there was enough charge to jump the connection, but would fail when the charge dropped ( which the BMS dictates when the battery is fully charged, or under acceleration) ?


I'm assuming the same issue as suspected in their thread - loose connection. Has anyone else had this issue?


Cheers,
Steve

[Eric SDV6SE]

There are a number of earth points on the car, any one of them can cause gremlins if a poor connection. Sounds like the new alt and battery have sorted most of your issues, but still check your earth's and major connectors, use a good contact cleaner. I note that a failed/ing alternator can quickly destroy a new battery, so always a good starting point.

[drivesafe]

There are a number of earth points on the car, any one of them can cause gremlins if a poor connection. Sounds like the new alt and battery have sorted most of your issues, but still check your earth's and major connectors, use a good contact cleaner. I note that a failed/ing alternator can quickly destroy a new battery, so always a good starting point.
Hi Steve and as Eric posted, check all your connection but pay particular attention to the earth cable from the motor to the body.

There is a common problem where this cable's connection to the body, can rust.

If so, you will need to remove the cable, clean rust and cold gal the area.

[Steve86]

There are a number of earth points on the car, any one of them can cause gremlins if a poor connection. Sounds like the new alt and battery have sorted most of your issues, but still check your earth's and major connectors, use a good contact cleaner. I note that a failed/ing alternator can quickly destroy a new battery, so always a good starting point.



Hi Steve and as Eric posted, check all your connection but pay particular attention to the earth cable from the motor to the body.

There is a common problem where this cable's connection to the body, can rust.

If so, you will need to remove the cable, clean rust and cold gal the area.

Thanks for responses. Should have made clearer that the list of actions included in original post were done by another owner with similar issue to mine.

After a couple of short runs with no issue we decided to drive an hour across Perth on Xmas eve. Car ran fine on the way up but we had the fun of no air-con on the trip back the next day (only 42 degrees!). It seems that this intermittent fault occurs more frequently when the car has not been driven for 24 hours, alternator/battery issue may be potential cause but as it's only been occurring for a few days is hard to say.

Are the earthing cables under the bonnet or run through the frame? Had a look yesterday & I think the two pics below show the battery & engine earth cables (I'm in no way mechanically competent). From what I can see the connections look ok.

We're already booked in for a service in a couple of weeks, but if anyone knows a LR electrics specialist in Perth I'd appreciate contact details if it stumps my mechanic.


175902

175903

Cheers,
Steve

[Eric SDV6SE]

2nd photo is correct, I believe there is an identical one on the opposite side of the engine bay. First photo not so clear, all I can tell is the battery terminal.

[josh.huber]

Thanks for responses. Should have made clearer that the list of actions included in original post were done by another owner with similar issue to mine.

After a couple of short runs with no issue we decided to drive an hour across Perth on Xmas eve. Car ran fine on the way up but we had the fun of no air-con on the trip back the next day (only 42 degrees!). It seems that this intermittent fault occurs more frequently when the car has not been driven for 24 hours, alternator/battery issue may be potential cause but as it's only been occurring for a few days is hard to say.

Are the earthing cables under the bonnet or run through the frame? Had a look yesterday & I think the two pics below show the battery & engine earth cables (I'm in no way mechanically competent). From what I can see the connections look ok.

We're already booked in for a service in a couple of weeks, but if anyone knows a LR electrics specialist in Perth I'd appreciate contact details if it stumps my mechanic.


175902

175903

Cheers,
Steve

Steve in the first photo the negative post looks like it's in the wrong spot, like it's broken, plus is there an extra earth wire on it? The orientation of the terminals post looks weird

[drivesafe]

Your motor to body earth cable is located down in the back of you wheel arch.

The first photo is your cranking battery negative terminal and that THICK cable bolts to the arch next to the inner guard, behind the fuse box.

The two studs in the second photo are earth points for electrics.

SPECIAL NOTE, the nuts on those studs once removed and then rescued, can work loose. I replace those nuts and all similar nuts with nylock lock nuts.

Those Land Rover nuts are a one-time-use nut and if you have to remove them, throw them away and replace with lock nuts.

[Steve86]

Steve in the first photo the negative post looks like it's in the wrong spot, like it's broken, plus is there an extra earth wire on it? The orientation of the terminals post looks weird

Will have to go through service history to see when battery was last worked on but it'd be odd if this was the cause of issue that's only just started to happen. By extra earth wire you're referring to the thinner wire?

I'll put up a better photo showing the battery in a couple of days. Would be good to compare it to a standard setup.



Your motor to body earth cable is located down in the back of you wheel arch.

The first photo is your cranking battery negative terminal and that THICK cable bolts to the arch next to the inner guard, behind the fuse box.

The two studs in the second photo are earth points for electrics.

SPECIAL NOTE, the nuts on those studs once removed and then rescued, can work loose. I replace those nuts and all similar nuts with nylock lock nuts.

Those Land Rover nuts are a one-time-use nut and if you have to remove them, throw them away and replace with lock nuts.

The thick cable is an earthing cable then? Was hard to tell as there's not much space to look behind fuse box.

Good to know nuts are one-use only



2nd photo is correct, I believe there is an identical one on the opposite side of the engine bay. First photo not so clear, all I can tell is the battery terminal.

Thanks, I'll have to check the RH side when I get home in a couple of days.

[DazzaTD5]

Over the years I've had odd continuity issues with mostly D4 models but have managed to fix them.
A good percentage of these had continuity issues between a plug and a module such as the abs.

Oddly enough or not but mobile cranes and mobile elevated work platform were extremely prone to this sort of failure, constantly.

I've had one particular customers D4 that after each time I "fixed" it, it would perform faultless (i think even for months) and then suddenly fault again.
Thankfully it never took a dump while they were in a remote part of the country.

It is now with the auto electricians I have used for many years and hopefully they find the fault as there is no way I am simply going to shoot the parts cannon at it until either its sorted or the customer is broke. That to me in an unacceptable (but oh so common) method of repair.

[shack]

is no way I am simply going to shoot the parts cannon at it until either its sorted or the customer is broke.

Parts Cannon.... Beautiful

[ScottA]

Hi All,

So we managed to get a month into disco ownership before an issue came up.

While driving we have a number of items intermittantly turning off & on including temp gauge, air con, central display unit, parking sensors, indicator display. Fortunately there's no mechanical shut-offs & speedo, lights, indicators (external) etc continue to operate. No warning messages until the car is switched off & a whole bunch flash up. It clears when the car starts up again.

Very similar issue reporting in this thread:
2012 LR4, electrical issue. Dash go blank while driving. - Land Rover Forums - Land Rover Enthusiast Forum (https://landroverforums.com/forum/lr4-38/2012-lr4-electrical-issue-dash-go-blank-while-driving-96794/)

Quote from thread:

So take your pick on what fixed mine:
1. New alternator, which was badly needed anyway
2. New BMS, which was also reset a few times
3. Refurbished instruments, but they had other issues anyway
4. New battery, the new battery I previously fitted was not holding charge properly, but that could have been caused by the electrical issues as I was getting some strange charging behaviour
The problems still persisted and became more frequent until:
5. I played with the wiring in the centre console ( lots of large connectors carrying the HS and MS can bus there and most of my faults related to the MS canbus)
One more instance of the faults, then nothing since.

Personally I suspect a dirty connector. It would work intermittently when there was enough charge to jump the connection, but would fail when the charge dropped ( which the BMS dictates when the battery is fully charged, or under acceleration) ?


I'm assuming the same issue as suspected in their thread - loose connection. Has anyone else had this issue?


Cheers,
Steve

Hi Steve,

MY D3 has just started showing the same issue (Christmas Day as well). Had it serviced 22/12... I originally thought it was the heat, but reading around the issue, my symptoms are the same as everyone else's.

My mechanic is excellent, although I'm not sure about how his team is for technical electrical stuff, so I'm not sure if I will take this problem to him.

Which auto electrician do you use?

Regards,

Scott A.

[Steve86]

Hi Steve,

MY D3 has just started showing the same issue (Christmas Day as well). Had it serviced 22/12... I originally thought it was the heat, but reading around the issue, my symptoms are the same as everyone else's.

My mechanic is excellent, although I'm not sure about how his team is for technical electrical stuff, so I'm not sure if I will take this problem to him.

Which auto electrician do you use?

Regards,

Scott A.

Hi Scott,

The points in my original post were quoted from another forum (and user) - I've only had my D4 for a few weeks so hasn't yet seen a mechanic or autosparkie while I've had it.

I also thought might be heat related but the issues have continued this week in the cooler weather. Temp gauge always drops out, then air-con/temp controls & sometimes the head unit turns off. I get a whole bunch of error messages if I turn off the car while the issue is occuring but it starts up fine with no errors displayed.

Looking through the reciepts from the previous owner there's no record of the alternator or battery being replaced. I'm thinking it may be a loose connection or charge issue. Car is booked for a service on the 13th so that will be the 1st time I'll have someone looking at it. Will post updates on how it goes.

[ScottA]

Hi Steve,

My bad, I confused your post. It was Dazza who mentioned the sparky....

+++++++

Hi All,

My issue also seems to be worse after the vehicle has been off for a while. My symptoms are eerily similar to others documented previously, but for completeness:

door locks cycle twice about 3-4 secs apart,
dash info panel loses data (except for avg fuel consumption),
hazard lights operate but don't show on the dash,
air cond fan goes off,
10-20 secs later the error message "vehicle fault, system shutting down" appears on the radio/CD info panel,
Time disappears from the radio/CD info panel.
Some time later everything starts up again.


If this happens on first turn of the key, the vehicle will not start. If it is already running, it will remain running.

I will check the connections into the rear of the head unit per suggestions on the other thread quoted by Steve, but any other suggestions welcome.

Many thanks,

ScottA

[Steve86]

Hi All,

My issue also seems to be worse after the vehicle has been off for a while. My symptoms are eerily similar to others documented previously, but for completeness:

door locks cycle twice about 3-4 secs apart,
dash info panel loses data (except for avg fuel consumption),
hazard lights operate but don't show on the dash,
air cond fan goes off,
10-20 secs later the error message "vehicle fault, system shutting down" appears on the radio/CD info panel,
Time disappears from the radio/CD info panel.
Some time later everything starts up again.


If this happens on first turn of the key, the vehicle will not start. If it is already running, it will remain running.


So have an update after finally getting the car back from service. Mechanic had checked fault codes & there were many, so reset them & told me to come back if the issue happended again so we could confirm which one(s) are relevant.

I managed to get about 500m down the road from the garage before the issue showed up. Immediately turned round & got my mechanic to run diagnostics.

Fault code is for a loss of communication with the body control module - U0140 (loss of voltage).

Next step will be to check the BCU & clean connectors (2 hr job).

[ScottA]

So have an update after finally getting the car back from service. Mechanic had checked fault codes & there were many, so reset them & told me to come back if the issue happended again so we could confirm which one(s) are relevant.

I managed to get about 500m down the road from the garage before the issue showed up. Immediately turned round & got my mechanic to run diagnostics.

Fault code is for a loss of communication with the body control module - U0140 (loss of voltage).

Next step will be to check the BCU & clean connectors (2 hr job).

Well, an update from me too. The D3 has been in the workshop for over 2 weeks (Indy). They have recognised the loss of comms with the BCM as a cluster issue (as have a number of UK posts I have read) so we’re waiting for the cluster to be reconditioned (about $800 + labour + ouch).

Will update further when I have more info.

[HarryO]

Had a very similar thing on my old D3 - refer
D3 Intermittent Fault (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/224041-d3-intermittent-fault.html)

[Steve86]

Had a very similar thing on my old D3 - refer
D3 Intermittent Fault (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/224041-d3-intermittent-fault.html)

Thanks Harry,
Mine went through a check & clean of BCM connections but still has the original issues. Fault codes still direct to a BCM issue, was yours showing any other codes to indicate an issue with the Instrument Pack?

Also, was the BCM changeover straightforward - my understanding was that they're synced to each vehicle & reprogramming can only be done by LR.


My mechanic has reached the limit on what he's able to do, we are now looking for someone specialising in LR electrionics to assist. If anyone can recommend someone in Perth that would be really appreciated!

[Ferret]

...My mechanic has reached the limit on what he's able to do, we are now looking for someone specialising in LR electrionics to assist. If anyone can recommend someone in Perth that would be really appreciated!

For Landrover specific electrical specialists in Perth - Autocode (https://www.autocode.com.au/) without doubt

[shanegtr]

Well, an update from me too. The D3 has been in the workshop for over 2 weeks (Indy). They have recognised the loss of comms with the BCM as a cluster issue (as have a number of UK posts I have read) so we’re waiting for the cluster to be reconditioned (about $800 + labour + ouch).

Will update further when I have more info.
I've had canbus cluster issues twice with my D3. First time I had the cluster repaired:
No start issues (https://www.aulro.com/afvb/l319-discovery-3-and-4-a/251482-no-start-issues.html)
Second time a couple of years ago now, had very similar issues with the repaired cluster. I ended up just getting a cluster from the wreckers and its been fine since

[Steve86]

For Landrover specific electrical specialists in Perth - Autocode (https://www.autocode.com.au/) without doubt

Finally got around to providing an update:

So I booked in with Mark at Autocode to take a look at the disco last month, good bloke to deal with - very knowledgeable.

Issue is with the medium speed canbus, however they couldn't get the fault to occur while plugged in to diagnostics to pin it down to a specific cause (cluster, BCM, harness wiring). That was a couple of weeks ago, since then has not faulted despite trying our best to do so. Until it starts playing up again (hopefully never) we've hit a dead end. I do wonder if it could be hot weather related...

[Gravy]

Back in the eons of time I was advised by a very good mechanic that the biggest mistake made by vehicle manufacturers was to not fit an earth connection between the battery negative terminal and the engine block, From personal experience this connection will cure many issues experienced with ignition electrics and improve engine performance. Any voltage drop will affect any engine electrical system performance.

Applying this simple process may resolve your unreliability problem.

[Steve86]

So can finally provide an update & resolution to the electrical issue.

After several months of good behaviour it started again last week. Got it to Autocode & they were able to observe it faulting while plugged in to diagnostics.

Ended up being a wiring short on the medium speed Can bus. Repaired & seems to be running fine.

Not a cheap fix due to needing several hours manually testing to find location of fault plus time to remove & replace panels etc, but more than happy to recommend Mark at Autocode for doing a good job.

[josh.huber]

So can finally provide an update & resolution to the electrical issue.

After several months of good behaviour it started again last week. Got it to Autocode & they were able to observe it faulting while plugged in to diagnostics.

Ended up being a wiring short on the medium speed Can bus. Repaired & seems to be running fine.

Not a cheap fix due to needing several hours manually testing to find location of fault plus time to remove & replace panels etc, but more than happy to recommend Mark at Autocode for doing a good job.


It's always good when they don't start throwing parts at it. As my mate says, mechanical issues, 1hr to find 10 hr to fix. Electrical issues 10hrs to find, 10 minutes to fix

[DieselLSE]

Ended up being a wiring short on the medium speed Can bus.

Can you advise where the short actually was?

[Steve86]

It's always good when they don't start throwing parts at it. As my mate says, mechanical issues, 1hr to find 10 hr to fix. Electrical issues 10hrs to find, 10 minutes to fix

Yep - was charged exactly 10 hrs of labour.



Can you advise where the short actually was?

Was told it was wiring running under the front passenger seat - I assumed power seats are on medium speed can bus?

[DieselLSE]

Was told it was wiring running under the front passenger seat...
Interesting. I have a theory that it is more likely an overlooked but, in hindsight, a heavy trafficked area where wiring can be compromised. By that I mean an area where the wiring may be being moved or rubbed or exposed to excessive heat etc. Under electric seats is not a benign area, particularly if the space is used to house tools etc., or if rubbish is left to accumulate. Or, of course, it could just be bad luck or a bit of dodgy wiring!

[350RRC]

Interesting. I have a theory that it is more likely an overlooked but, in hindsight, a heavy trafficked area where wiring can be compromised. By that I mean an area where the wiring may be being moved or rubbed or exposed to excessive heat etc. Under electric seats is not a benign area, particularly if the space is used to house tools etc., or if rubbish is left to accumulate. Or, of course, it could just be bad luck or a bit of dodgy wiring!

Mouldy pizza trays and half empty travellers will cause all sorts of mayhem.

DL