Hi All,

I've been writing a topic in the other part of the forum My 2006 4.2 SC, but in delving into the high speed CANBUS I'm getting very heavily into the technical bits and thought this part might be better placed here.

In short, car is throwing errors and seems to be having trouble communicating with the ABS module in particular which has been replaced already, and I wanted to check whether the bus itself is operating properly.

Given I'm cleaning all of the interior bits and carpets anyway, I'm disconnecting modules from the bus as I go and testing how it behaves. This has been a big job:

Have you disconnected the PCM?

Does every L322 have a PCM? Is that the parking brake module?

This car has an old fashioned cable driven handbrake with a lever, not a switch. I had somewhat convinced myself it doesn't have one...

Is this it in the picture?

Click image to enlarge

PCM - powertrain (engine) control module. However unlikely to cause the short circuit when switching on accessories but the BCM or whatever the main fuse box is called in your model sounds more likely.
Do you have a wiring diagram for the canbus? I have one for my MY12 but not for yours.

This for MY10-12 might be of some use.

https://www.fullfatrr.com/gallery/albums/u...peed~1.pdf

Thanks Graeme.

Yes, have had the PCM disconnected then which doesn't seem to be the source.

The wiring is closest to the "L322 2006 wiring circuit diagrams" in the wiki, but notably not quite the same, the in/out pins on the PCM connector are reversed for one and also I don't think the transfer case module forms part of the spine. This document does say "VIN 239036 onwards (RHD)" and mine is about 5000 prior to that, which might make it an oddball changeover time vehicle.

I did manage to answer one of my other questions in that there are other non-CANBUS twisted YB/YN pairs which go to the mid range speakers in the B pillar from the amplifier in the rear.

Actually, at this point I'm thinking this shorting seeming behaviour might be normal and just an artefact of trying to read the system with a multimeter when it's active.

Good news at the moment is that I've managed to actually clear most of my errors in the modules and I think digging them out and fiddling with all of the connectors may have relieved some of the communications lost DTCs.

The suspension module might have been played with before and I am now wondering if that is the source of my issues, as it is the only module with a fault that won't clear now being "Invalid data from DSC (ABS) module". No other modules are complaining about data from the ABS module at this point.

IIRC "Invalid data from DSC (ABS) module" is a "standard" always there fault..

When BMW sold up they left several fault codes that appear in all cars and I'm pretty sure that is one of them, should make no difference to the workings of the fatty.... There again, yours might be young enough to not have them.....  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

I assume that you have the e-diff introduced for the 4.2 SC but not the TR system which was introduced in MY07 and that your suspension module has a single connector, being pre-TR. Your diff housing should be the same as MY07 onwards for which the e-diff was optional.

I am pretty certain I don't have the E diff despite being a supercharged. Housing looks like the attached and there are no electronics, solenoids or anything around it that I can see:

Well I've sourced a RQT500181 module and plugged it in, no particular change to the problems I'm having although I'm not 100% on whether it's 100% compatible or not.

New errors that came with putting in a new module are:
- C1A28 - Wrong number of LED's illuminated
- U1A35 - VIN Data - signal compare failure
- V1A84 - Vehicle configuration data - System programming failure - is not configured

Notably C1A00 missing calibration and U0416 invalid data from ABS are both still present.

Before receiving and changing the module I was playing with the calibration on the old one and the car could be made to sit at the right heights and pump itself up and down to do so, although it seemed as though the next time it started the heights would all be wrong again and needed to be calibrated every time. It does drop slowly in the rear over a week or so.

Any ideas on what I should try next? The HDC not available and amigos are on at all times and can't be cleared, just immediately as soon as the ignition is turned on every time.

Have you calibrated the steering angle sensor?

ABS will throw codes and HDC / TC unavailable warnings will show up if it's not been calibrated following tinkering.

Jon 1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

Hi Jon,

This is just start car, full lock left, full lock right, centre wheel yes?

Sadly makes no difference. For what it's worth the live display seems to correctly show the direction the wheels are pointing and the adaptive lights turn on some extra left/right turning lights at low speed so it seems to be functioning as well...

I've just run out to try the steering calibration again and the dash is reading transmission fault again, this one I've been able to clear before but it's notable that it's come back, transmission module is also reading U0416 and nothing else.

Checking CANBUS resistance it was showing shorting again after turning the car off and this time not resolving itself after a period of time like it was before, pulling and replacing available module plugs I've got it reading 700 Ohms again which is still incorrect, is something I've had before and I can't strictly work out which thing is causing that reading yet.

It's not always just lock to lock on vehicle start-up, if you have a LR specific tool (like a GAP IID or similar) then put it into learn mode for the steering sensor calibration.

Jon 1992 RR Classic 3.9 efi Vogue
2014 Disco 4 HSE
===================
Both my fatties now gone...
Previous: 2011 L322 4.4 TDV8 Vogue SE /// 2002 L322 4.4 V8 HSE /// 2009 Discovery 3 2.7 TDV6 XS /// 2004 Defender 90 TD5 /// 1993 110 V8 Snatch Landrover /// 2005 Discovery 3 2.7 TDV6 SE (Aus) /// 1990 110 Isuzu 3.9 County (Aus) /// 1976 Series III Trayback (Aus)

A couple months worth of progress from me - zero. At least in terms of making any improvements to the errors getting thrown up by the car.

I have picked up a little oscilloscope for some more deep diving into the CANBUS operation, and what I think I've learned is that the bus reading short circuit to itself/ground when the system is "awake" is normal when just checking with a multimeter?

Checking the bus with the oscilloscope is telling me that it is at least functioning somewhat as expected, with CAN HI and CAN LO showing opposing signals centred around 2.5 volts. The signal seems very busy/messy but that might be a limitation of the cheap scope I'm using. Looks like this:

Click image to enlarge

Personally, I'd be concentrating on these codes...