L322 2002 L322 EMS ECU dead all of a sudden?

Hi everyone,

I'm about to start pulling my hair out. About a week ago, my L322 began to make all sorts of clicking and clanging sounds around the chain on bank 2. I pulled all the belts to confirm it was the chain and not one of the other components. It was still the chain. After that, I pulled the valve covers and figured out it was a lower chain tensioner that got stuck. We ran the car with valve covers off to verify that it was the tensioner, the car ran just fine (solely on distribution, no auxiliary pumps, alternator, or anything like that, so I know it ran on pure battery). Engine was running no longer than 5-10 seconds at a time in that configuration, 'cause well, you get an oil bath

So, I replaced the tensioner. Chain tension seemed much better, and I wanted to crank the engine again to see whether it really helped, only to see that I got the HDC, ABS, DTC, and all those "usual" failures, but on top of that - the engine doesn't even try to crank.

My first thought was - that the battery drained past 8.5V - EMS ECU wouldn't respond. Disconnected the battery, left it on a charger overnight, and am getting a 12.3V from it now - nothing. What's more interesting is that none of my diagnostic tools (I have a large variety of those) is capable of connecting to and reading out EMS ECU. All the fuses, including the main 50/100A ones, are good. The steering column unlocks, so I'd assume immo ECU is also operational. I can read out everything but engine ECU.

Could it go bust all of a sudden? What am I missing? Power lines seem to get power all over the place where I could reach. I tried disconnecting and reconnecting every ECU (apart from LCM, but that one's readable, so dunno if that would help anything). I'm gonna try and feed the starter 12V to see if the engine wants to crank in general, but if the engine ECU is unreadable, I'd assume it will crank but still won't start on key turn.

Does anyone have any ideas? Or am I SoL and just need to get a new ECU?

Thanks,
Vlad

12.3 volts is a flat battery, not much use on one of these power hungry beasts.
Fully charging the battery and seeing what voltage you have an hour after coming off charge would be my starting point. you should see 12.8 volts, no less than 12.7.

Datatek said:

12.3 volts is a flat battery, not much use on one of these power hungry beasts.
Fully charging the battery and seeing what voltage you have an hour after coming off charge would be my starting point. you should see 12.8 volts, no less than 12.7.

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I see, that's a great insight. Thank you. I'll probably just go get a fresh battery and see if that gives, before I do any other motions.

Edit:
I've pondered for quite a while now why LR didn't fit a double battery into these..

favoretti said:

I see, that's a great insight. Thank you. I'll probably just go get a fresh battery and see if that gives, before I do any other motions.

Edit:
I've pondered for quite a while now why LR didn't fit a double battery into these..

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If you buy a new battery, it will need charging for at least 24 hours before fitting.
JLR are too tight to fit a double battery and in your case it would still be dead.

My l322 pulls 30-50A as soon as i turn the ignition on. That's without running the engine.

BTW, I got this car with a 920A 110Ah battery (Bosch S5 015). Is that something that actually should live there? Quick googling says it should be good enough, but just wanted to confirm. Thanks again!

I think that's about the biggest that will fit without making changes

favoretti said:

BTW, I got this car with a 920A 110Ah battery (Bosch S5 015). Is that something that actually should live there? Quick googling says it should be good enough, but just wanted to confirm. Thanks again!

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That is OK assuming that being discharged has not ruined it. Modern car batteries do not recover well from a complete discharge.

So a new battery at full charge (battery tester says 100/100%) - ignition on, Trans failure, HDC inactive, ABS, DTC and no connection to EMS ECU still... I'm gonna build the engine, since the new tensioner is in there, but I'm kinda still stumped.. The only wire that's disconnected is MAF, I can't imagine that would make any difference. A bit of oil getting on coil connectors can't be that bad either to blow up the ECU, right?

Could be another ECU preventing communication on the CAN BUS ? You said above all the others connect, but do you get sensible data from all of them ?

Dunno about L322 but some other cars have diagnostic line that pass through other ECU's. (Vauxhall Corsa does this)

favoretti said:

So a new battery at full charge (battery tester says 100/100%) - ignition on, Trans failure, HDC inactive, ABS, DTC and no connection to EMS ECU still... I'm gonna build the engine, since the new tensioner is in there, but I'm kinda still stumped.. The only wire that's disconnected is MAF, I can't imagine that would make any difference. A bit of oil getting on coil connectors can't be that bad either to blow up the ECU, right?

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Is your transfer box motor plugged in?
Is your gearbox still plugged in?
Can you speak too the gearbox ecu or abs ecu at all?
Do the relays click on in the ecu tray?

stustrong said:

Is your transfer box motor plugged in?
Is your gearbox still plugged in?
Can you speak too the gearbox ecu or abs ecu at all?
Do the relays click on in the ecu tray?

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Transfer box motor is plugged in. I can talk to transmission ECU and get sensible data out of it, ABS ECU also responds. When I turn the key trying to start, I hear relays click in the "ecobox", next to the ECU. I've read on the net that LCM can jam the canbus, so that's something I'm gonna try next, unplug that one... other than that - will try checking whether starter gets 12v on key turn and try feeding separate 12v to the starter... My current working theory is that the starter might be blown, but what puzzles me is that EMS ECU just doesn't respond to diag.. ABS ECU reports timeouts to the EMS ECU, so does AT ECU..

Completely gutted here... Luckily I did some chiptuning on the car, so I have ECU files backups, but the question is - can I just get a different ECU off the net and reprogram, or will that screw more things up than it will fix? LR dealership doesn't even want to look, cause L322 is "too old".

So I got it to run again... Apparently, whatever I've done to the batteries, it was still undervoltage. What sold it out was something I was altogether not paying attention to. The temp gauge went off the charts as soon as I turned the ignition on. Once I got a way more powerful start help attached - the gauge went down to a "cool" state, and it started cranking and starting. Distribution will still need to be replaced, but at least my ECU isn't fried, and it runs... Disassembling for the chain replacement now..

Thanks, everyone, for thinking with me and your ideas!

So I'm back at square 1 again... Distribution done, timing seems to be ok, but was idling a bit rough. I wanted to do an adaptation reset, as some people say it's required after Vanos mods - turned off the engine - back to ECM no start. Check engine light doesn't show in ignition 2, dashboard flickers as it apparently tries to start the ECM, but temp gauge doesn't go back to cool state and I can't crank the engine... What the actual heck.. It ran for about 20-25 mins with alternator connected and all that, one would say it should be able to fire up the ECM? Even with the same starter booster that did it last time - no dice.. What can it be? I'm assuming even if I did all the timings on the distribution and all that correctly - this ghost starting problem will keep chasing me forever now?

PS. I know this is a UK forum, but anyone here from NL by any chance? I'm getting seriously desperate and local dealerships aren't taking 2002 RRs

I don't know where or even if there are 2, but when you are in this condition have you checked the coolant temp sensor/wiring?

J

marjon said:

I don't know where or even if there are 2, but when you are in this condition have you checked the coolant temp sensor/wiring?

J

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From what I know there are 2 on the water pump, and there's one on the lower left hose of the radiator (if looking at it from the front). Even when I disconnect all 3 - there's no difference in behavior and I do get voltage on the wires.

Coolant temp gauge is a symptom of the fact that ECM doesn't power up (at least that's my current working theory). Once it sits still for a while and I fire up like 200A power booster - I get it to fire up the ECM occasionally and am able to start the car.. That's what's puzzling me the most...

Have you checked the ignition switch?

As Datatek said, the early L322'a absultely devour battery power, anything less than full chaff ie: 14.7 volts when running and 12.8 at least when not will throw up ALL sorts of anomolies that seem to make no sense. The first thing I did when I got our Rangey ,same model as yours but a 2006, was to replace what looked like a perfectly good battery but didn't look right' to me. Has paid back the price in droves, removed any weird stuff my brain created and allowed proper scanning. For the price of a new battery it is a 'gimme'. Datatek was also correct about modern batteries, if you drain them totally they rarely recover! Best of luck with your travails and remember, if owning and running and old Range Rover was easy, everyone would own one!

favoretti said:

Coolant temp gauge is a symptom of the fact that ECM doesn't power up (at least that's my current working theory). Once it sits still for a while and I fire up like 200A power booster - I get it to fire up the ECM occasionally and am able to start the car.. That's what's puzzling me the mos

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Ok so getting a 12v booster out can sometimes get it going, but your battery is good?
Have you checked the power to the ECM when it won’t?

J

Will do more measurements tomorrow. But as for the battery - which brand and capacity would gurus recommend?