Diagnostic System failures...confused!!

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Saint.V8

Dyed-in-the-wool 100% RR Junkie
Full Member
Those that have followed my threads will know I have recently suffered a blown HID/Xenon lamp which caused allsorts of havoc with the car...The usual HDC/EAS/ABS/DSC failure and also some strange light show with the instrument cluster (IKE) as per the Youtube Vid below!

https://www.youtube.com/watch?v=BGr2J-j3JHk

Since all this, I have not been able to connect to the diagnostic systems on the car using the All Comms....

I have two laptops with the All Comms software loaded on it, one with the original Version 1 and a second with both Version 1 and Version 2 of the software....and I cannot connect with any of them.

I also have a generic OBDII ELM327 Scanner which does connect to the car and can read the engine ECU perfectly well and still bring up live engine data....so that confirms the socket is at least connected to the engine ECU and there is power to the OBD socket.

Reading up on the various data buses on the BMW's that the L322 is based upon would indicate an issue on either the I/K bus or the D bus. Also following some reading on BMW and L322 forums would suggest the most common causes are the Headlamp ECUs or the Levelling ECU....I have disconnected all these in turn and all together and still no luck in connecting.

I have a good strong battery and alternator output, the rear quarter is dry as a bone and all connections are corrosion free....

I attach a document on the various data buses and associated tests, but most of the high level testing needs to be done using the BMW DIS system, of which I have for my BMW 735, but I have never got it to talk to the Bimmer correctly and so I now use the BMW INPA for the Bimmer diagnostics....so would not know if I could even get DIS to work on the L322 as I can't seem to get reliable results connecting it to the vehicle is was specifically designed for rather than a vehicle that shares basic system components!!!!

To diagnose the I/K bus it suggests disconnecting each ECU in turn until you are able to connect to the diagnostic systems again...this could be a long winded process as there are many of them!

Reading the document further says the I/K buses work differently to the CAN bus in which the ECUs provide the line voltage, on the I/K buses there is a Master and Stand-by controller which provides the line voltage for the system to operate.

Depending on if the L322 is based on the High Line version of the BMW E53 (X5) and E39 (5'er) and also the E38 (7'er) then the Master for the K Bus is the GM Module (I can only assume the BCU on the L322 is the equivalent of the BMW GM (General Module)) and the LCM is the Master for the I Bus with the IKE (Instrument Cluster) as the Standby.

The I Bus (Information), K Bus (Body Control), D Bus (Diagnostics) and CAN Bus (Controller Area Network) all cross communicate via a 'Gateway' which is the IKE (Instrument Cluster).

Diagnosis of the ECUs connected on the I/K Buses is carried out over the I or K bus respectively and the D Bus is used to wake these units up into Diagnostics mode and deliver the information back to the OBDII socket(also the D Bus is used to connect to the DME (Digital Motor Electronics)).

I am fairly sure my D Bus is working as I can use a generic Scanner to interrogate the Engine ECU and this doesn't use the IKE unit at all...it just connects directly to the Engine ECU.

But in order to talk to the other ECUs on the I/K Buses or the CAN, the communication has to go through the 'Gateway' (IKE) and also either the Master or Stand by Controller (IKE or LCM or the GM) have to be working in order for communication to happen.

Now for my theory........

Considering the HID Lamp blow and the IKE (Instrument Cluster) went fecking haywire as a result....my thoughts are this sudden surge of electricity or spike has shot up the wiring somewhere through the LCM and into the IKE....

In order to communicate on the I Bus you need either the Master (LCM) or the Stand by (IKE) to work.....

What are the chances that this spike has taken out the I Bus in both the LCM and the IKE....as the instigator of this was a blown bulb (which is controlled via the LCM) and then the IKE played up....the two units required for I bus diagnostics...and all of a sudden I cannot connect using the All Comms.....????

OR, what are the chances my All Comms hardware has developed a fault at the exact same time and the car is actually fine???? Maybe I need to find another 2002-2005 L322 to test it on!

Car starts, drives and all systems work perfectly....just can't connect via All Comms.....

Any thoughts people....(well those that have managed to read all the way to this point without going cross-eyed that is :D:D)
 

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Great understanding of the system mate :)

Think you first need to check your comms on another 322
Then if that's okay, possibly change your LCM for another unit

Think it's time you invest in a FaultMate, it makes the necessary programming of these new components possible

If you was more local, I'd be more than willing to lend you a hand

Good luck
 
Nightmare, as Hippo said, need to verify the Allcomms on another car as a first step. Sadly I doubt that is the problem. Given the voltages used for HIDeous lighting, I think your voltage spike up the derriere is highly likely.
 
Great understanding of the system mate :)

Think you first need to check your comms on another 322
Then if that's okay, possibly change your LCM for another unit

Think it's time you invest in a FaultMate, it makes the necessary programming of these new components possible

If you was more local, I'd be more than willing to lend you a hand

Good luck

Thanks for the offer Ellis, if I get totally lost, I may just make a trip to your part of the world and cry on your shoulder if that is OK with you!

Nightmare, as Hippo said, need to verify the Allcomms on another car as a first step. Sadly I doubt that is the problem. Given the voltages used for HIDeous lighting, I think your voltage spike up the derriere is highly likely.

Just seems strange that looking at the Databuses in the BMW document and also the Diagrams in RAVE, the Engine ECU and Gearbox ECU are independent of the IKE and are such by law, as the regulations state the engine emissions and control system must be able to be read independently of the other vehicle systems....

So what confuses me is the generic scanner will connect to the Engine ECU but the All Comms won't.....and yet the Engine ECU diagnostics doesn't go through the IKE 'gateway', it only shares its information via the CAN bus to the IKE and not its diagnostics....so surely the All Comms should still connect to it as it is a totally separate databus to all the rest??

I may email the legend that is Storey Wilson for his input!
 

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Thanks for the offer Ellis, if I get totally lost, I may just make a trip to your part of the world and cry on your shoulder if that is OK with you!



Just seems strange that looking at the Databuses in the BMW document and also the Diagrams in RAVE, the Engine ECU and Gearbox ECU are independent of the IKE and are such by law, as the regulations state the engine emissions and control system must be able to be read independently of the other vehicle systems....

So what confuses me is the generic scanner will connect to the Engine ECU but the All Comms won't.....and yet the Engine ECU diagnostics doesn't go through the IKE 'gateway', it only shares its information via the CAN bus to the IKE and not its diagnostics....so surely the All Comms should still connect to it as it is a totally separate databus to all the rest??

I may email the legend that is Storey Wilson for his input!
I guess that may depend on how the Allcomms operates. It may need to establish other comms first for example. Only Storey would know the answer to that.
I take it the Allcomms powers up and that the OBD power is present?
 
I guess that may depend on how the Allcomms operates. It may need to establish other comms first for example. Only Storey would know the answer to that.
I take it the Allcomms powers up and that the OBD power is present?

That is my thought at the moment too Keith...that the All Comms needs to handshake with the IKE first before communicating with the DME.

I have emailed the legend for his advice.

OBd powers up OK and so does the All Comms, I have asked Storey if there are any self tests I can perform on the All Comms to check that...

It is most perplexing, I may pop down later and have another look and see if anything glaringly obvious rears its head....

I also tried last night the battery disconnection and short the battery leads for 20 minutes trick to see if that would do a hard reset...but the results were the same!
 
This is a very common problem with the aging L322 Range Rover. The K bus or Diagnostic bus can become locked out by just one offending vehicle ECU. A good analogy would be a house full of old phones and one phone is off the hook, thus preventing anyone else from using the phone system.

The most common offending ECU, is one of the headlight ECUs or the headlight leveling ECU. Usually disconnecting the ECU from the vehicle solves the problem. Please see the following video on the problem.

Range Rover MKIII - Troubleshooting L322 Range Rover K Bus

Your generic engine OBD tester would not have any trouble communicating because it is on a completely different communications bus.
 
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This is a very common problem with the aging L322 Range Rover. The K bus or Diagnostic bus can become locked out by just one offending vehicle ECU. A good analogy would be a house full of old phones and one phone is off the hook, thus preventing anyone else from using the phone system.

The most common offending ECU, is one of the headlight ECUs or the headlight leveling ECU. Usually disconnecting the ECU from the vehicle solves the problem. Please see the following video on the problem.

Range Rover MKIII - Troubleshooting L322 Range Rover K Bus

Your generic engine OBD tester would not have any trouble communicating because it is on a completely different communications bus.

Many thanks for your reply Storey, I had watched your vid a few times when this problem reared its head.

I had tried disconnecting the Head Lamp ECUs one at a time and also the Leveling ECU in various combinations and unfortunately I still could not connect to diagnostics.

I may well try and disconnect the LCM and try again...but I am fearful that disconnecting a key ECU in the system and turning the car on to check may log faults that I am unable to clear due to lack of communications....what are your thoughts on this? Can I disconnect the LCM with causing major havoc?
 
Can you attempt to connect to the Air Suspension ECU and then close communications. Then send me the debug log file with today's date. I will look at the log file to see if anything else may be going on or if the vehicle is just not able to respond. Just email the log file to me.
 
Can you attempt to connect to the Air Suspension ECU and then close communications. Then send me the debug log file with today's date. I will look at the log file to see if anything else may be going on or if the vehicle is just not able to respond. Just email the log file to me.

Certainly will, I will do this in the next couple of hours for you once I get back home (in the middle of another endless shopping trip for the new baby! :D:D:D)
 
Ant, remember than fault i had with my rear parking sensors ? it turned out that the allcomms wasn't communicating with the PCD ECU once i sent him that debug file he could see what was going on, he will sort it i have alot of faith in storey....
 
Ant, remember than fault i had with my rear parking sensors ? it turned out that the allcomms wasn't communicating with the PCD ECU once i sent him that debug file he could see what was going on, he will sort it i have alot of faith in storey....
So true, the guy is a fecking Legend....

I am in email cahoots with Storey at the moment, I sent what I had and he has replied with a way to get a debug file (as mine wasn't created) so he can take a gander, which I will do this evening.
 
Debug file sent to the legend that is Storey Wilson.

He has confirmed the K Bus is no doubt up the shoot and the process of disconnecting the fuse to each of the K bus ECUs in turn and seeing if the All Comms will connect as removing fuses is easier than getting to each ECU...if doing that still fails, it is then onto physically unplugging each ECU in turn and repeating until the culprit is found...guess what my next few days is filled with??

Many thanks to Storey for his help and time answering emails...
 
Debug file sent to the legend that is Storey Wilson.

He has confirmed the K Bus is no doubt up the shoot and the process of disconnecting the fuse to each of the K bus ECUs in turn and seeing if the All Comms will connect as removing fuses is easier than getting to each ECU...if doing that still fails, it is then onto physically unplugging each ECU in turn and repeating until the culprit is found...guess what my next few days is filled with??

Many thanks to Storey for his help and time answering emails...
Just what you need with a new baby:doh:
What a joke the L322 is, if you had to take it to a dealer, you'd need a mortgage:rolleyes:
 
Just what you need with a new baby:doh:
What a joke the L322 is, if you had to take it to a dealer, you'd need a mortgage:rolleyes:

Certainly is a puzzle...luckily I have my BMW and her Fiat 500 so not totally reliant on the L322.

Yes, dealer diagnostics and fault finding would cost big bucks....I have always said, if you own a Range Rover either have deep pockets or a good grasp on which end of a spanner is which....nowadays with the L322 a good grasp of electronics and understanding the squiggles on a DVM/DMM dial are a definite must.

Can't DIY these beasts without your own Diagnostics...and also being a member of a good forum for advice and the help of the Legend that is Storey Wilson, who knows these vehicles very well, is a true bonus, I couldn't do it without the support from you guys on here!

UPDATE:

Tonight I disconnected the Headlamp ECUs, Headlamp Levelling ECU and the ABS ECU in turn and none of these tests brought the K bus back on line!

Tomorrow I will be taking out fuses, as the other ECUs are harder to get at...so first start with pulling the fuses, if that still doesn't achieve the desired result, it is time to start removing trim panels!

Here is a list of the fuses and things to check (screenshots from Storey Wilsons Vid - RSW Solutions - Troubleshooting L322 Range Rover K Bus - YouTube )
 

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