ECU fault

been trying to get my dad's D2 running the last while and having some issues!

Fitted a new clutch and then when doing a few other bits I noticed the intake housing of the turbotechnics VNT I had on it was cracking.

Ordered a new CR turbos VNT so was waiting a few weeks for that. When fitted took it for a short drive and everything seemed perfect. Had a few other bits to do before it went back on the road then to be ready for cvrt/mot.

Next time I went to start it, it would just crank and not fire. Was showing up injector long peak charge faults then.

Put a new injector loom into it but still showing a topside switch fault.


Tried a spare ECU I had and it started but if reved over 2500rpm, it would cut out and show up a topside switch fault then too.
Granted the spare ECU I had was unknown so maybe that wasn't right too my mate I got it off said it came out of a 110 that drove into his yard towing a trailer with a Cummins in it before getting the engine swap done.

I drove it for abit then while keeping rpm blow 2000 just to make sure it didn't show up anything else or cut out and not start like the first one.

Was low in diesel then so wouldn't start the next morning so filled it up again but when started, it was missing badly and showed up open circuit on injector 1 and 4 so left it be again until check the ECUs out.

The other day, I tried both ECUs in a friend's D2 that I was sure has no issues to start with and it starts and runs with both ECUs fine although still will cut out and show top side switch fault if go over 2500rpm.

Anybody have any ideas if it's something else that's causing it as no point throwing parts at it as trial and error if there's something going on with the loom or something and just blowing more ecus or injectors.

So it's clear that both ECUs are fubar but your vehicle seem to have a wiring issue too on the engine harness, not uncommon, just an example https://www.aulro.com/afvb/discovery-2-a/143155-d2a-td5-misfiring-cutting-out-engine-harness.html but it can be chafed anywhere... i've seen this on my own vehicle too long time ago... i bit the bullet and bought a bran new harness then

Thanks! Yea, it definitely seems like a loom issue although would have thought the issue would be in the part with the black ecu plug and plug to the injectors. Being a Discovery of course, swapping the section of the loom that has the black plug on it is abit of a pita as it goes in behind the dash and much more of a pain than a Defender.

I'll go through the loom in the places the guy in that link found as being a D2 and has the exact same issues, might get lucky. I have the short section with the red plug spare from a D2 I have for parts but think it's been cut

The engine was out not that long ago too to do the clutch and a few other bits which made it handier to just pull the engine rather than the gearbox and disturbing the loom might not have helped too.

DaveM-sport said:

Being a Discovery of course, swapping the section of the loom that has the black plug on it is abit of a pita as it goes in behind the dash

Click to expand...

The engine loom which contains that section doesnt go behind the dash and has only the red plug

Yup, realised after I was getting mixed up which section the injector loom was on.

Will swap the section and see and hopefully it sorts it. Annoying that is killed two ECUs of course!

Finally got round to getting at this. My dad isn't able to drive for a few weeks due to an operation so wasn't a major panic.

However, got a loom for it and stuck it in and another ECU but it refuses to start. just cranks over.

Brand new battery, no faults coming up and can activate all the injector solenoids with the nanocom.

Could it possibly be something wrong with the replacement loom such a crank sensor wire maybe?
Would have thought it would show up an open circuit or noisey crank signal fault however.

Did you make the ECU learn the security code in "utility"?

Yep. Code earned and ecu status as not immobilized

Can you see rpm input on live data while cranking? it must be above 250 for the engine to start... if it's manual try to clutch start it insistently

Checked it earlier and yup! Reading 0rpm on the live data so obviously crank sensor or the loom going to it is in trouble

Just to to tie this one up

Changed the loom for another one. Plugged it in and started up straight away with crank speed on the live data straight away