Sport 2008 2.7 RR Sport can bus problem

Gidday,

Back again after quite a while, been trouble free for a couple of years. Most unusual, but now back to normal, "Will my wagon start today?"
A few days ago after driving home, message on the radio, "vehicle fault, system shutting down" and it did. Next day it happened a couple more times so i consulted doctor google only to find it happens often to lots of RR owners. Door locks cycle, radio, GPS, HVAC all shut down until it decides it wants to work again. Engine still runs, gauges work, but if turned off will not start again.

After trawling the internet it seems there are several causes, but i am unable to find a tried and true method of eliminating the different possibilities. I have scanned with snap on, Launch and autel scanners and have faults relating to canbus. I have had a fault code thrown up with park assist from day 1 (over three years ago) when i bought the vehicle, so i doubt that the park assist module is the culprit but i disconnected it today and the fault still occurred. After clearing faults and rescanning after shut down i get fault code "U0010-88 Medium speed CAN communications Bus -Bus Off" when scanning the dashboard.

Am i correct in thinking that if i disconnect items (ie radio, HVAC, GPS etc) one at a time that the component causing the fail, if disconnected, will not cause a shutdown?

Is there any one out there who can throw light or guidance on how i go about eliminating and pinpointing my issue without hurling money at it?

All help greatly appreciated.

First port of call would be make sure the battery is 100% a ok and the alternator is charging properly.

brianp38dse said:

First port of call would be make sure the battery is 100% a ok and the alternator is charging properly.

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As above ^^^^^^ low battery volts and/or a defective alternator play havoc with these vehicles

Got to admit, i haven't checked that but i have no starting issues, ie slow to crank, and the fault is so random and can occur whilst driving at 2-3000rpm i feel it is so unlikely. I will however drive and record live data with battery voltage today and see if anything unusual. I will also fit a new battery. The existing one is at least 4 years old and is probably getting near end of life.

That's on the change over year, known faults with earth on the main instrument cluster, strip repair and report back. If not different send the cluster off for repair.
We had todo this in the end with one we had in the fold but we scanned it with id 11 tool which gave us data suggesting the cluster we sent the data to the scan tool makers who confirmed the fault.

Fitted a new battery yesterday and fault still occurs. Old battery was on its last legs, so not a wasted expense.

Prior to fitting battery yesterday morning i was in a no start situation. I had the existing battery disconnected and charging for a couple of hours intending to carry on diagnosis whilst waiting for new battery but the new one arrived and so i fitted it straight away and bang, away she went. After a few minutes, door locks cycled, outside temp and clock on dash disappeared and radio, HVAC shut down. I removed the cluster and again she sprang into life (cluster still plugged in but hanging there), but only for a few minutes and then shut down again. I tried wiggling the plug in the back of the cluster whilst the ignition was on and whilst cycling the ignition, but this appeared to make no difference.

I have been scratching around on the internet and hope fully today i can make some progress in learning how to pinpoint canbus faults. Im not entirely convinced its the cluster yet and don't want to risk sending it away for repair as A) there maybe nothing wrong with it and B) it may come back in a worse state than it went in.

biketeacherdave said:

hat's on the change over year, known faults with earth on the main instrument cluster, strip repair and report back. If not different send the cluster off for repair.
Biketeacherdave, Can you throw any more light on what i should be looking for if i dismantle the cluster?

Thanks

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Best to put a new battery on charge before fitting as it may have been sat a while on the shelf.

brianp38dse said:

Best to put a new battery on charge before fitting as it may have been sat a while on the shelf.

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+1 ^^^^^^^^^^^^^^^^^^^^^

Made a little headway today. Couldn't sleep (things on my mind) so up at 4am surfing the net and sussing out the can bus thingy. Pushed the boat out and bought a break out box to make checking the diagnostic port and comms easier and what a godsend.

Plugged it in and then plugged scanner into break out box and it made things so much easier. Instantly i was able to tell that the can bus (hi speed) was working as it should, but the medium speed was playing up intermittently. I found a wiring diagram of the can bus network and on the diagram it shows can bus hi and can bus low controlling lots of stuff, but the other network (the one that is faulting) is shown as a VAN (Vehicle Area Network) that operates at lower speed. On the break out box, i could see the can bus leds flickering to indicate voltage pulse and was able to measure hi and lo outputs as they should be at pins 6 and 14 but only one led on the van system (pins 3 and 11) was flashing and that was pin 3. I measured the voltage at pins 3 and 11 and was getting 2.7 and 2.3 respectively and the system was not in fault mode. When the system faulted, i noticed the led at pin 11 flashed and then shutdown occurred and pin 3 stopped flashing. At this point there is no voltage at pins 3 and 11, (hope this is all making sense). I removed the dash and checked for power at the cluster plug on the van network. No power as it was shutdown, im guessing at the gateway (cluster i believe) or by the becm.
Cleared all fault codes and when the vehicle came back to life, i carried out a vehicle scan and recorded no comms between instrument cluster and audio interface and no comms between cluster and HVAC. However if i went into audio or HVAC with the scanner i was able to communicate with both. so i am thinking it is a fault with the cluster. Please back me up.

Does anybody have any idea how the van system should display on a break out box? On the wiring diagram, it lists both van wires as "van" whereas the can bus are listed as "can bus hi" and "can bus low".

I am unable to find much about the van system on the internet and i am not sure if i should be getting similar behaviour to the can bus.

Hope this is not too boring not just gobbledegook. All inputs greatly received.

Spadgr

Probably not your problem but he has some good educamational vids.

Thanks for the heads up, watched half a dozen of his Videos and he is the man. I wish he lived next door.

Battery now fully charged, and indeed it was down at 33%, although i had spent a couple of hours running Diagnostics on Thursday.

No further progress, still trying to figure out the root cause. Most fault codes point to the instrument cluster, but i am unable to communicate with the rear diff control module or the vehicle dynamic control module. so i will find their location and make sure that i actually have them fitted to my model.

Rigged up an oscilloscope and checked the can bus and van patterns, but both looked the same and neither looked like the ones i have witnessed on the internet. Maybe i need a crash course on oscilloscopes.

Will make a few enquiries and see if i can find a reputable company in NZ that i would be comfortable sending my dash to and maybe take a punt on that.

Time for a bit more diagnostic dan. Hopefully he will put me on the right track.

Any help or tips greatly appreciated.
Cheers

spadgr said:

Most fault codes point to the instrument cluster, but i am unable to communicate with the rear diff control module or the vehicle dynamic control module.

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Are you sure that the vehicle has an active rear diff? Most don't as it was a seriously expensive option, hence it's seldom fitted. If the rear active diff module isn't fitted, you'll not see it on the CAN.