ECU blues?

[Catmatt]

Got a mate with an 02 TD5 Defender. It was running fine but has been in the shop for some major gearbox and TC work and when they finished - they couldn't get it started.

Firstly the battery was so low it wouldn't crank the engine so they hooked up a booster battery and .....Crank's fine - but no running engine.
1. They swapped the original crank position sensor back on to the car rather than use the CPS that came with the gearbox and TC and still nothing.
2. Hooked up their diagnostic gear (Not a Nanocom) and over 20 faults presented. They couldn't read the fault codes so in desperation, my mate called for some help so I took my Nanocom and manual down to the shop.

The 20+ faults are a quite bizarre ranging from "Auto transmission errors" (It obviously doesn't have an auto) through to "driver speed error" etc etc.

It took my 4 attempts but finally I managed to clear half of the errors but there are still quite a few "Logged" errors....and the engine still won't start. The shop have run out of options and are scratching their heads (They are a reputable 4WD repair business)

I'm suspected a corrupt ECU due to the under-voltage attempts to start it and the erroneous error codes??????

I don't suspect the immobiliser due to point below regarding key-fob.

History -

Car has a 2 plug ECU and is not, repeat not an electronic fob-key. Key into door lock opens all doors and simply unlock steering lock through the ignition key and away you go! Key turns everything on, will crank the engine but no go Joe.....

It was running fine went it went in but mysteriously now won't start. Only has 120K and is in good condition.

Anyone got an idea how to get it to burn some diesel????

[Tusker]

Gearbox work you say...

There's a gearbox earth that causes all sorts of issues when not connected back up.

Mine's an 03, various lights dimmed, would start but wouldn't stop on the key. This was when picking up from the dealer. Show them the key with car running outside - they blamed a turbo timer, which it's never had. Back up on the hoist, earth reconnected, all good.

I've since heard similar stories about this earth concerning other marques. It causes really strange faults.

Regards
Max P

[Recy Mech]

Right, firstly the disclaimer: I haven't owned a Landy for years and the army ones didn't have ecu's. I've only gotten back into Landys because my daughter is buying one.

Anyway, from working on MTU's, CAT, Cummins, and Duetz, I'd have a guess and say because the battery discharged way under the ECU's memory voltage its lost all memory and requires to be re 'flashed'. That is the software for that particular engine has to be loaded into the ECU. Or, has someone done some welding on the vehicle and the ECU has been 'spiked'?

If possible go for a re 'flashing' of the ECU.

[Dan]

Are you 100% sure the immobilser has not been triggered into shutting things down?
When you put power direct to the starter motor and it cranks over does it start the motor then die a second or two later or does the motor not fire up at all when it is cranked over?
This may help confirm whether it could be the factory immobiliser. I have a 2000 Defender with the same key system (no fob) and had big problems with my immobiliser shutting down my ECU.
With power direct to the starter motor, it would crank over and fire but died a second or two later.
If yours cranks and does not fire at all, maybe the problem lies elsewhere.
People suggested I try disconnecting the battery leads and holding them together for 30 seconds as this can 'clear' an ECU sometimes.
Also, low battery voltage can cause issues but it seems you've checked this already.
This advice from AULRO member Xtreme may be useful if the ECU settings have gone wrong for some reason: http://www.aulro.com/afvb/electronic...n-news-27.html (http://www.aulro.com/afvb/electronic-diagnostics/110127-new-nanocom-evolution-news-27.html) (especially posts 255 to 260 and 267) He lists the correct Australian settings for the Td5 Defender, especially the one that enables/disables the Immobilizer.
Good luck.

[Catmatt]

Are you 100% sure the immobilser has not been triggered into shutting things down?
When you put power direct to the starter motor and it cranks over does it start the motor then die a second or two later or does the motor not fire up at all when it is cranked over?
This may help confirm whether it could be the factory immobiliser. I have a 2000 Defender with the same key system (no fob) and had big problems with my immobiliser shutting down my ECU.
With power direct to the starter motor, it would crank over and fire but died a second or two later.
If yours cranks and does not fire at all, maybe the problem lies elsewhere.
People suggested I try disconnecting the battery leads and holding them together for 30 seconds as this can 'clear' an ECU sometimes.
Also, low battery voltage can cause issues but it seems you've checked this already.
This advice from AULRO member Xtreme may be useful if the ECU settings have gone wrong for some reason: http://www.aulro.com/afvb/electronic...n-news-27.html (http://www.aulro.com/afvb/electronic-diagnostics/110127-new-nanocom-evolution-news-27.html) (especially posts 255 to 260 and 267) He lists the correct Australian settings for the Td5 Defender, especially the one that enables/disables the Immobilizer.
Good luck.

Thanks Dan,

I'm starting to lean towards the factory immobiliser even though it doesn't have a key-fob. The corrupt ECU was a last resort although it can occur with an under-voltage.

Have tried the sequence of numerous key on-off and depressing the accelerator but still no joy.....

Good point with crossing the battery leads discharging residual energy out of the ECU....it's an 'oldie but a goodie' and I didn't think of that.

Also had a thought to check/reset the fuel immobiliser on the firewall (I didn't think to see if it was depressed so will give it a push tomorrow)

I'll post results later tomorrow afternoon - Cheers!

[Catmatt]

Well....like I was taught as a young apprentice - always go back to the basics and eliminate all of the potentials, and probables as you fault-find.

So we back-tracked all of the wiring - shop mechanic on the drivers side and me on the passenger side.

I found a blown fuse among the spaghetti junction of wiring in the battery box under the passenger seat and a power wire that had pulled out of a crimp fitting - fixed/replaced.

Mechanic found a small on/off switch used for a clock/timer that had the power and earth wires loose so they were touching occasionally - re-soldered.

He also found that that 1 of the 2 main plugs into the ECU was not fully home - so he pushed it into it's ECU slot with a satisfying "Click" and................. EUREKA - Its alive and running!!!!:o;):p:eek::D:):)

Have now cleared all of the faults and it runs like a gem! Time to go for a long drive and charge the batteries - my mate is pleased and the worried frown has left his face :cool:

Moral of the story - try not to solve a problem until you actually know what the problem is! ;)

Thank you for the helpful replies Defender types!! (I'm a Disco owner)