Member Since: 21 Oct 2016
Location: kent
Posts: 13598
Here’s some pics for u ref ground points, plus using a test light is also very useful as it puts the circuit under load as it can sometimes pass ok using a multimeter but fail with a test light
Indeed worth checking the large connectors at the back near side wheel arch , plse also note that some of these diagrams are for LHD so connectors may be on the opposite side
Hope this also helps
Behind drivers side wheel arch liner
Drivers side headlight
Behind main fuse box
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Behind Passenger side wheel arch liner
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Last edited by gstuart on 20th May 2023 9:58 am. Edited 1 time in total
19th May 2023 12:19 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13598
Other connectors which are very important , behind passenger side wheel arch liner and the others rear wheel near side
Full wiring diagram and workshop manual, plse wait a little while for them to fully open , then press download after there open , once again sorry if you’ve already seen this
Member Since: 21 Oct 2016
Location: kent
Posts: 13598
Also when the rear wishbones were replaced was it the uppers that were done and if so was 4 x wheel alignment done after
Indeed if u accidentally forgot to remove the battery when welding it can cause untold issues , but of course understand it was just a simple mistake
Assume all ur battery has been tested with the engine off and engine running to ensure the battery m alternator weren’t damaged
The alternator also uses a big ground wire , drivers side behind liner
19th May 2023 12:37 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13598
Just copied ur thread here to save us having to go back
Indeed see what ur gap iid will communicate with and then work ur way through each one in turn to ensure ur getting the correct Vdc and ground signals
Hope this is also useful to u
timmyt79 wrote:
Hi All
Sorry to hijack this post but there is so much valuable information here that its a shame to repeat/lose any of it.
So im having the same problem with cluster lighting up like a xmas tree...temp gauge in red..hazards etc.
Cluster has been sent away and returned from repair place but still the same...have spoken with them and they assure me that it has been repaired and tested so im reluctantly ruling that out for now..
Bit of background...had to strip all back end and replace all rear suspension arms,shoes etc including new struts.Lots of welding was needed on sills and rear crossmember etc.All done and put back together but when i tried to start,nothing...just the IC problems.
NOW...i stupidly started welding without disconnecting the battery I did remove it after i realised but i had already started....i also knicked a few wires in the rear loom but re-soldered them and have thoroughly checked all the loom and cannot find any more breaks.
following Gstuarts excellent guide i have checked via a brfeakout box attached to obd socket, pins 3+11 (60 ohms) but pins 6+14 im getting 123ohms!
all my grounds have passed testing and im getting battery voltage at pins 16-4 and 16-5
I have dissconnected abs connector and tested pins 14 -35 but getting 'OL' so i believe that is an issues as should be getting 120 ohms if im correct?
Im really starting to get very disheartend now as worked so hard to get her back on the road as she has a lot of sentimental value so dont want to scrap becaus eof a wiring issue.
Any help will be greatly received
19th May 2023 12:39 pm
timmyt79
Member Since: 18 Oct 2016
Location: Pemrokeshire
Posts: 585
Many thanks Gstuart...again your a plethora of knowledge!
I have been away all week and then straight back to work so havent been able to spend any time with Disco sadly.
ALL my rear suspension has been renewed inc air bags....not had any alignment done as cannot start the car!
A second hand ABS module has arrived so i can try that and at the same time ill try and bypass the EPM.
Will get back to you with results
28th May 2023 8:01 pm
timmyt79
Member Since: 18 Oct 2016
Location: Pemrokeshire
Posts: 585
Quick update,managed to get under Disco this morning...bypassed the epbm and replaced abs unit with a known good used one,cleared all the codes and still having the same issue
Have stripped all wiring and cannot find any breaks,all connectors seem good.
All earth points are good and running cable from engine block to battery negative just in case.
Full battery voltage at obd socket.
So back to Ohms reading of 123 at pins 6+14....this is obviously my issue but where is it?!!!
My code reader is Not picking up TCCM,PCM or TCM
Heeeeelllllppppppppp!!
29th May 2023 10:07 am
timmyt79
Member Since: 18 Oct 2016
Location: Pemrokeshire
Posts: 585
Ok little update......
I think my battery is goosed...Remember i mentioned that i forgot to disconnect it whilst welding?
Its a Yuasa HSB5019 only 3 years old...noticed whilst having it on charge that its only getting to approx 12.6 (off vehicle) Then when i check it with multimeter 10 min later its already dropped to 12.3v.If i reconnect it and try bridging the starter relay it fails to turn the crank other than very slowly.
So..my guess is that whilst welding i have made a bad earth with the welding ground and its made its way to the next best ground spot which is the battery/chassis,causing the internals of battery to fry?
Am i right in thinking that although the voltage should technically be enough to power all the ecu's etc that the amperage being put out/demanded from the battery is not enough to power all the ecu's on the High speed canbus circuit hence causing all the issues?
Next step is to replace the battery,luckily its under warranty,waiting for my mum to send the receipt to me (that she luckily kept) as she had it changed 3 years ago when she was lending it!
Any thoughts?
Will keep this thread posted
31st May 2023 9:24 am
timmyt79
Member Since: 18 Oct 2016
Location: Pemrokeshire
Posts: 585
Hi again.
Current situation.....Brand new battery fitted.
Sadly no change...all faults still present
Have tried jumping the started solenoid with key in position 2 and car turns over well but wont fire.Immobiliser light is still flashing on dash and wont extinguish.....is this significant and can it be overridden somehow?.
Starting to wonder if the main ecu is fried?what with having battery connecte dwhilst welding and i also had a charger on whilst batteyr was still connected to car over the months i was working on it.
7th Jun 2023 9:04 am
onetwentie
Member Since: 25 May 2020
Location: West Yorkshire
Posts: 61
Hi Timmyt79
Sorry to hear mate that you are still struggling. I have been following your posts in the hope of seeing some good news.
Forgive me if you have done so already, but have you done the relevant mustimeter tests at the OBDII port? checking the HCAN high and low for the right resistance?
I took off the driver's side wheel arch liner yesterday to look for a broken ground in case that was the issue for me, but it was fine. I know you have been tracing wires, but have you checked your grounds too? Gary posted some links to where to check on the car.
Keep at it, you will get there in the end!
7th Jun 2023 3:21 pm
timmyt79
Member Since: 18 Oct 2016
Location: Pemrokeshire
Posts: 585
Thanks for the reply..
Yes taken all ohms readings etc,although may run them again with a now known good battery.I had a 123ohms resistance at pins 6+14.
All grounds seem good.
all connections seem good.
brain fried....
7th Jun 2023 3:32 pm
onetwentie
Member Since: 25 May 2020
Location: West Yorkshire
Posts: 61
you are welcome sir..
just reading your last message and cross checking with the information that I was given.. I'm sure that it should be 60ohms unless one of the resistor 'ends' is open?
That's the same reading I got too until I managed to spray contact cleaner into the connector block behind the rear wheel arch (passenger side).
So I deffo think you should check those readings again.
Also be mindful as I got two different results, the first time I was using normal probes, then I bought the thinner 'back probes' and got different readings.
Worth getting those back probes.
7th Jun 2023 3:41 pm
timmyt79
Member Since: 18 Oct 2016
Location: Pemrokeshire
Posts: 585
I purchased one of these https://www.amazon.co.uk/dp/B0BCJNTBGL?psc...ct_details
And found it invaluable.
May be of benefit to you?Good luck with your continued fault finding.Im currently between night duty so will tackle it again tomorrow
7th Jun 2023 3:50 pm
onetwentie
Member Since: 25 May 2020
Location: West Yorkshire
Posts: 61
Can I ask a dumb question.. what does this do? or what can you do with it? I know Gary was looking at doing something with one of these to create a simulation of something..
7th Jun 2023 4:13 pm
timmyt79
Member Since: 18 Oct 2016
Location: Pemrokeshire
Posts: 585
Not dumb at all mate
i am by far no expert,Think Gstuart is the man to talk to about all the all the features but what i have found is that effectively its a;Much easier to test the different pins on the obd port and b;gives me a physical indication of a good ground and power.Also you can still have obd reader connected whilst you are testing pins etc.
Worth the few quid imo
7th Jun 2023 4:34 pm
gstuart
Member Since: 21 Oct 2016
Location: kent
Posts: 13598
Plus 1 to the break out boxes
This was the one I got and found this video which hopefully helps in a small way showing it’s capabilities
When I had problems i also plugged my Autel MX808 diagnostics into the breaker box
Know there are things like a canbus sniffer where it can go into the system in more detail but personally stayed with the breakout box
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I did remove it after i realised but i had already started....i also knicked a few wires in the rear loom but re-soldered them and have thoroughly checked all the loom and cannot find any more breaks.
