Globetrotter448 wrote:

GS, thanks for that info as it will come in handy at some time. I am a hoarder for information related to LR3. Am I correct in thinking that the resistors are only at the start and finish of each buss. So the 120 ohms measured means the fault has put the resistors in series.

  

Briscoe05 wrote:

Stuart, your knowledge is impressive. I am going to look at the disco shortly so will confirm readings. If I unplug the tcm and measure at the obd will I get an incorrect reading as it's no resistor fitted?

Only items with resistor fitted does that mean if unplugged wont start?

Cheers,
Nick

  

Briscoe05 wrote:

So I checked the grounds and I get 0 on the grounds which is good.

I get battery voltages pin 16-4 and 16-5

I get 2.7v 6 to ground
I get 0.875v 14 to ground.

As good as grounded this one.

So the second readings u have ie, 0.875v means there’s a ground issue

Try using a jump lead from ur battery neg post to the the engine , there’s a lifting bracket on the RH side of the engine as u look at it

U can confirm it’s a good ground before hand by setting ur multimeter to ohms and going from the neg battery post to that clamp, that will confirm before u use a jump lead that’s it’s a good ground

Plse let us know how u get on with the tcm and earth lead ,

  

Globetrotter448 wrote:

Trying to follow this. When you measure the HS Can bus you get 120 ohms. As the bus has 120 ohms on each end (both ends in parallel give you the 60 ohms) it indicates you have an open somewhere on the bus.
My first step would be to check each of the items GS shows in the diagram for connection. At each connector you could check the bus resistance back to the previous connector. If you have 120 ohms then that part of the bus is okay so plug it back in and move to the next connector. If all test okay, which should be impossible, then it may be one of the modules. I believe there is a way to by-pass modules, with a cable, for the resistance check so you can trace a faulty module.
Lets know how you go.

  

Briscoe05 wrote:

So I checked the grounds and I get 0 on the grounds which is good.

I get battery voltages pin 16-4 and 16-5

I get 2.7v 6 to ground
I get 0.875v 14 to ground.

As good as grounded this one.

————————————-

I’m just copying some data over next to ur results

Have been going through some wiring diagrams for the last few hours so plse ignore , as I’m just trying to see if another test will work , got to work ot out first in my head



————

The 120 ohms resisters are in the instrument panel and ABS module

Please try this

Pins 4 & 5 are grounds, check these are ok using ur multimeter , if after ensuring pin 16 gives u ur battery voltage , ie 12.6Vdc , go from

Pin 16-4
Then pins 16-5 , this will test ur grounds as u should read the battery 12.6 Vdc

Then with battery connected

Pin 16 is ur battery voltage , should be around 12.6vdc

With ur multimeter test

Pin 6 to ground , should have around 2.7 Vdc
Pin 14 to ground , should have around 2.3 Vdc

From what I’ve also read pin 6 and pin 14 should add up to 5 Vdc

If pins 6 or 14 are zero Volts means it’s grounded

If u get a low reading on pins 6 or 14 try removing ur instrument panel to access the wiring and wiggle the wires to see if the Vdc changes , if it does, try to start the disco

Click image to enlarge

  

Metsonline wrote:

I have a hs canbus fault,cannot read ecm,tmmc and vdm others are readable but with canbus related faults was reading a thread which involved a member called gstuart and was wondering if he came to a conclusion,I have a 60 ohm reading on ms canbus but high speed is 120ohms,does anyone know the loop route from instrument cluster to abs which I believe is the Start and finish,looking to find out how to check this loop
Vehicle has immobiliser light flashing when ignition one,temp gauge reads hot with light on,various warning lamps,suspension,handbrake etc and will not crank,there seems to be a lot of people on this forum that have had very similar faults but from what I’ve seen of the build quality so far I’m not surprised ,any help would be very much appreciated

  

gstuart wrote:

So I’ve finally found the connector for the ABS , is also the place where the other 120 ohms resisters is fitted inside the module

Apologises going off on a tangent , am wondering if after disconnecting the battery if u test between pins
14 and 35

In what ohms reading u get please , seeing it’s very easy to get to and can easily remove the back cover whilst the connector is still fitted to the module

So if u would be so kind to disconnect ur battery and set meter to ohms and see what readings u get on the above pins

Then take out battery and check the TCM module and carefully check the canbus twisted wires on the connector and after disconnecting the connector to see what the pins are like on the TCM module

If all ok please also do the same with the engine control module behind the box

Many thks

Click image to enlarge

Click image to enlarge

I have done the TCM and ECM pin checks, both are good and no damage or corrosion I will be sure to test the pin numbers for ohms and come back to you, thanks again for all the help its massively appreciated. it's really wrecking my head.