4JX1 ECU burnt

[quinnd]

Has anyone else experienced the 4JX1 ecu high voltage circuit for injection burnt out usually due to alternator/battery problems? I have repaired 2 in the past but I cannot remember the transistor part number that I used to drive the 12v side of HV coil. It is always so smoked out that the original part is unrecognisable

[Meat-Head]

No you bot an invoice to look at or can your supplier pr

[Meat-Head]

iny. Chunkking sidding iphone

You have old invoice?

Csn supplier pront you what a list if stuff you buyer off them

Hate iphone

[Fool2cool]

Quinnd do you have any information on this repair? I'd be interested to read up on it.

Thanks
Fool

[quinnd]

iny. Chunkking sidding iphone

You have old invoice?

Csn supplier pront you what a list if stuff you buyer off them

Hate iphone
I had been mucking around with it for ages fitting all kinds of bits and smoke was getting out etc and then finally one combination just worked and i got high frequency humm out of it, and sure enough 115V or whatever was there, sweet put the lid on and shipped it off without taking note of bits, thought i'd never see one again ahhh, whoops

[sherl645]

Hi,
I have a good Ecu if I can check anything on it for you?
Ronan

[quinnd]

Thankyou so much, I understand if you dont want to open yours up though. Attached is a picture of an old one arrow indicates tranny that burns out and usually there is a tandem spot next to this which on mine is empty. I need to know the number of the arrowed transistor

[sherl645]

Hi,
I have a few of them. It's no problem. I'll look on Monday for you.
Ronan

[Meat-Head]

Hi,
I have a few of them. It's no problem. I'll look on Monday for you.
Ronan


If it is no problem for you.

that one transsiter could you unsolder it - then measure the resistanse with your meter on the board below and the transsister it's self.

OFF TOPIC- BUT RELEVENT:-

i have an arc welder that went bang - the triac exploded, replaced no work - open circuit power supply - so next poor sod that looks this thread up can measure the resistance, or voltage if you can power one up and it's saved for ever more

thanks

meat

[quinnd]

One thing I did do in the past was send an email to the manufacturer and ask them what their part number was. They did actually reply but said it was made specifically for that purpose and it was confidential. Bugger me these cars are 10 years old now- like it matters. Maybe someone with more brain cells can figure out what it should be. I never had a scope at the time to check "on' times but it drives that toroidal, with back emf charging those big green caps, well that the way I saw it working

[quinnd]

Hey Meat how are you on Suzuki immo related stuff? I put up a thread on a Vitara http://www.digital-kaos.co.uk/forums/f178/2004-grand-vitara-poss-immo-off-321408/
whats your thoughts?

[Meat-Head]

what about robbing a edc15 or edc 16 ecu see what is in there?

[quinnd]

They just run 12v injector for solenoid type. The 4JX1 uses 110VDC (?) it is the HV supply that craps out in the ecu

[Meat-Head]

They just run 12v injector for solenoid type.

disagree 70 volts common rail might be so 'lumpy' your meter reads 110volts

there is a thread by omigaicalumuncail or someone - ford pube avatair

'how does ecu get 70 volts to the injectors' or something

i'm offline knackered nite nite

[genius76]

IR 814c or similar and check nearest diodes

[quinnd]

Hey thanks Genius, I see your ecu actually has that transistor installed in the spot where mine is empty. It looks like both work in tandem? Have you crossed that original part to the 814c?

[genius76]

MOSFET mate

[quinnd]

MOSFET mate

Thanks I thought it was a MOSFET just wondering where you got the 814C from? Original looks like 846, or 848c 7521

[quinnd]

According to IR websire 7521 is the part number. 846C is the date code

[genius76]

difirent for europe and for azia iven 35xx can found
i mend that ecu programet diferent for difirent countres

[quinnd]

I think this is what I after to replace the 7521 MOSFET
N channel P10NK80Z
The SuperMESH? series is obtained through an
extreme optimization of ST?s well established
strip-based PowerMESH? layout. In addition to
pushing on-resistance significantly down, special
care is taken to ensure a very good dv/dt
capability for the most demanding applications.
Applications

HIGH CURRENT, HIGH SPEED SWITCHING

SWITCH MODE POWER SUPPLIES

DC-AC CONVERTERS FOR WELDING, UPS
AND MOTOR DRIVE

[Meat-Head]

Thanks I thought it was a MOSFET 7521


Metal Oxide Semiconductor Fileld Effect Transister - knew that since i was 8 daddy told me.

Where did you get that photo at 1 am genius? amazing

[genius76]

Metal Oxide Semiconductor Fileld Effect Transister - knew that since i was 8 daddy told me.

Where did you get that photo at 1 am genius? amazing

OFF TOPIC

I big fan of GOOGLE - AUTOCOM - NOKIA 3100C - MY WIFE AND MY KIDS mate :)

Long time ago i VERY VERY accurately read how to use GOOGLE :)

[quinnd]

Opened ECU today, 7521 MOSFET triggered in 900uS pulses, but when powered on pulse is rapid and then slows to half approx. The pulse is still way too slow I think. In the past, (when successful) I would get high frequency humm and 110 volts produced by back emf, through diodes etc and stored in 4x caps and ready for injectors. Obviously driver circuit is ok but frequency generator is crook. Hopefully whats left of my donor ecu will have the necessary parts :hmmmm2:

[genius76]

Thei pointing on diodes mate, short cirkuit
Some guys found corroded tracks, on the edge of the circuit board

[genius76]

what differenced between yours and this one
why transistor on other port

[quinnd]

Thats one that I swapped bits around on so is in the other spot. That other picture is a real mess!

[quinnd]

Thei pointing on diodes mate, short cirkuit
Some guys found corroded tracks, on the edge of the circuit board

My diodes test ok, parts marked 7535?, and 8889 x2. 0.2V drop one way, no conduction in opposite direction
In this ecu i am repairing now it is very tidy, no components burnt, circuit board is good. I think MOSFET switching frequency is too low

[Meat-Head]

put it in the oven see if if it helps or frezze it see if it gets worse

[genius76]

anyway frequency impulse rate coming from?

[quinnd]

We now have 110V DC from the converter !

Now I need to know- There is a transistor marked in the picture, it appears to control the output of this 110 volts to H1 terminal in 5 pin socket. I checked on another vehicle but was not able to start it as engine was in pieces. Does it only output 110V while cranking then running or when oil rail is up to pressure or what?

[quinnd]

Even replaced this badboy (see pic)
When first switched on (on bench) check lamp would flick flick flick flick flick then steady on. So replaced MCU, not bad for someone with parkinsons :eek:
So anyway turned out it wasnt that, it was benchtop power supply not grunty enough to deal with initial charge-up of HV converter, connected battery and all was good

[genius76]

U REPLACED MCU AND AL OK?

[genius76]

My diodes test ok, parts marked 7535?, and 8889 x2. 0.2V drop one way, no conduction in opposite direction
In this ecu i am repairing now it is very tidy, no components burnt, circuit board is good. I think MOSFET switching frequency is too low


anyway frequency impulse rate coming from?

Why I asked you how you think :)

[quinnd]

No MCU was ok. I was checking voltage at H1 output only 0.4V
But at MOSFET indicated by arrow there is 110V, I am not sure if this gets switched on when ecu sees RPM or rail press or what?

[genius76]

RPM 100% MY OPINION

[Meat-Head]

Second above post

[Larue]

If it's still actual....
To get injection pulse output ECU needs to see:
1.Crankshaft position signal;
2.Camshaft position signal;
3.Oil rail pressure(at least 3.5MPa,if i remember right)
The engine MUST have right timing.
IF ONE OF THESE THINGS IS MISSING,OR ENGINE TIMING IS INCORRECT - NO INJECTION PULSE.
Best Regards
Larue

[quinnd]

If it's still actual....
To get injection pulse output ECU needs to see:
1.Crankshaft position signal;
2.Camshaft position signal;
3.Oil rail pressure(at least 3.5MPa,if i remember right)
The engine MUST have right timing.
IF ONE OF THESE THINGS IS MISSING,OR ENGINE TIMING IS INCORRECT - NO INJECTION PULSE.
Best Regards
Larue
Thanks. Is this specific to the 4JX1? This ECU works differently to normal common rail, ecu supplies constant 110V and then switches each injector to ground just like normal efi. Except much faster obviously. The question was what conditions need to be met for ecu to output the 110V before rail pressure is up to then start with inj pulses

[Larue]

Sorry that i did get you wrong.
This all ISUZU 4JX1 common rail system works different way than anything else.
I can't say about conditions inside ECU, but about outside i would say it needs all power supplies,grounds etc. which should be there.
Do you need pinouts for ECU?

[quinnd]

No but thanks for the offer. Just waiting on another garage to complete some engine work on a different vehicle so I can try this ecu before I send it back to where it came from

[Cobra429]

Needs rail pressure, cam and crank signals in correct phase before ECU will trigger injectors. Injectors are NOT fed constant 110 volts and grounded by earth. We have one with a faulty ECU at present that gets low voltage signal to injectors but not high voltage required to actuate injectors. Have seen also in peugeot common rail engine that had capacitor fried. And also injector driver (DC to DC converter) on a Denso V4 pump that had 12volt signal but no 150 volt required to drive spill valve. Both were non runners

[quinnd]

Thanks, yes we did discover that it is not constant 110V but only stored inside ecu ready for the drivers to pulse them. I sent it back to the customer and havnt heard so I guess my repair was a success