Technical ECU repair. Is it possible to DIY?

[Scoobysnacks]

As the thread title really. Does anyone know what work is actually done to repair the ecu? Is it something that a reasonably skilled home mechanic could have a go at? I'm handy with a soldering iron, and happy with electronics.

 

[shaun200765]

This is something i've been wondering about myself for a while now.

If the output stage for the HT coils is just a transistor affair then yes, i'd say its doable

 

[Scoobysnacks]

What's the betting it's all on chip, and they just swop the chip out?

Anyone got any schematics or tech drawings for the ECU's? Don't want to pull mine to bits if it'll damage it.

 

[DaveMcT]

Its probably a power transistor that's gone but the wrong impedances could mess up the trigger points. Open it up and see if the part is available from RS Components or similar

 

[Scoobysnacks]

Haha, how brave am I feeling?

 

[DaveMcT]

The ECU repair folks open them up, so that much cant be too hard.

If the parts cant be got then box it up & send it for repair. If the parts are available - fire up the soldering iron.

 

[Scoobysnacks]

Well, had the ECU off today, undid the 4 bolts that hold it together, prised the back off and...

Turns out that that just frees the main body of the ECU from the heat sink, and it's all still sealed inside. :bang:

Looks like it's held shut with some kind of melted plastic plug, so not sensibly accessible when I need to use the car that afternoon! I'll have it all to pieces when I've got a day to work out how to put it back together properly!

Anyone know how to tell what model of ECU you have? The piece of paper that has it written on doesn't any more! :bang:

 

[Scoobysnacks]

The ECU repair folks open them up, so that much cant be too hard.

If the parts cant be got then box it up & send it for repair. If the parts are available - fire up the soldering iron.

If it turns out to be easy, might take on a few of them, I'm sure I can undercut them!

Course I can't actually test them, but that's a minor point!

 

[DaveMcT]

Course I can't actually test them, but that's a minor point!

That could be a snagette

 

[paul12345]

You wont be replacing chips in these ecus as they are hybrid, they dont have chips in packages, the dies are soldered directly to the board.

The good news the coil problem normally is a burnt out track in the corner of the ecu which you can solder a wire across.

You would need to crack open the plastic case with a screw driver/hammer, clear the clear gel from around the area then solder.

 

[Scoobysnacks]

Ok, if it's just track burnt out (why do Fiat insist on under engineering the electrics on their cars? I've had numerous connectors and electrics burn out on this thing?) then it's do-able. What is the clear gel? Is it some kind of heatsink paste? Do I need to replace it? Also how do I go about fixing the plastic cover back on once it's fixed?

Now I'm not entirely sure if it's an ECU problem again, I still suspect TPS or an air leak. It's the intermittent nature of the problem that worries me. If it were a burnt track it would do it all the time surely?

I will try to lay my mitts on a 12v test lamp over the weekend and do the full ecu tests. I'm still confused as to why a coil pack should arc from the base of one of the HT connections to the mounting bolt. The only reason I could possibly think of is damp, or WD40 has suddenly become an excellent electrical conductor.

Bloody Fiats! :bang:

 

[reddy4bed]

The ecu's are designed and manufactured by others and sold to all manufacturers, so cant blame Fiat for that. Fiat commision the software no doubt.
You dont say what ecu type you have but guess its MM Iaw59f variety. I think work is done on these by drilling out the plastic securing fixing points and removing the black cover from pins. The o/p's are being repaired, so the parts (or equivalents) must be available.
Not attempted myself though.
Tony.

 

[Scoobysnacks]

The ecu's are designed and manufactured by others and sold to all manufacturers, so cant blame Fiat for that. Fiat commision the software no doubt.
You dont say what ecu type you have but guess its MM Iaw59f variety. I think work is done on these by drilling out the plastic securing fixing points and removing the black cover from pins. The o/p's are being repaired, so the parts (or equivalents) must be available.
Not attempted myself though.
Tony.

Fiat must specify the input/output parameters for the ECU's, so I still say it's their fault!



I have no idea which model number it is, which is one of the main problems. I'll go outside in a minute and pull it off, see if I can get it apart and see if there is any obvious damage internally.

I'm still suspecting TPS or an air leak too though, but have made sure everything is tight, and if I put my hand over the TB it stops the engine, so doesn't feel like there's a loss of vacuum. Is there a mass flow meter for the air? Could that be wrong?

I have the OBDII comms lead that I can plug into my laptop, but not sure it works properly (mainly because I don't know the exact ecu model number)

 

[paul12345]

it wont be the coil/ecu problem because as you said it would fire on 2 cyclinders all the time.

Could always use obd2 fiatecuscan to see if you can notice anything.

and I assume your ecu if the black typre ie Iaw59f m3/m2 does not really matter in fiatecuscan

 

[Hrabosh]

Did you get somewhere with DIY fix of the unit? Im now having the same issue and asking the same question...

 

[Ziggy122]

Did you get somewhere with DIY fix of the unit? Im now having the same issue and asking the same question...

Nit reallt a diy task as the stuff inside is well protected with a gel like

Most people send them off to be repaired

Ziggy

 

[ChristofSchwiening]

Dear All,
I am about to see if I can fix the ECU on my 2005 Fiat Panda 1.1. It is currently running very badly with little power and the OBDII spits out an error code of P0351. My local garage tried a number of things including the obvious spark plugs and (I hope) coils. They have concluded it is the ECU. I am looking forward to drilling the plastic and dealing with the gel! I will post back with the results - currently the car is heading to the scrap yard if I can't fix it, so there no reason not to try.
Greetings,
Christof

 

[Ziggy122]

Dear All,
I am about to see if I can fix the ECU on my 2005 Fiat Panda 1.1. It is currently running very badly with little power and the OBDII spits out an error code of P0351. My local garage tried a number of things including the obvious spark plugs and (I hope) coils. They have concluded it is the ECU. I am looking forward to drilling the plastic and dealing with the gel! I will post back with the results - currently the car is heading to the scrap yard if I can't fix it, so there no reason not to try.
Greetings,
Christof

Keep plenty of pictures!!
The more info the better

Ziggy

 

[s and b]

these arent repairable as its the wires thinner than a human hair that break
im sure i posted a few years ago the inside workings of these ecus
they are made on a machine that was made by dark matter.............. wales i think

 

[judderbar]

these arent repairable as its the wires thinner than a human hair that break
im sure i posted a few years ago the inside workings of these ecus
they are made on a machine that was made by dark matter.............. wales i think

When you see the inside of these hybrid ECU's you can believe the Americans are using Alien technology.