General Advice with ecus replacements

[Cibo]

Hi everyone

Re my previous thread on intermittent speedo failure due to water damaged mk2b non abs 54 plate.

Have had no joy with fixing this issue so thinking of changing bc unit, engine ecu and key set.Have found donor car with same numbered bc unit but know these are coded to each particular vehicle so my question is if I also replace the engine ecu and ignition barrel on my car with the ones from the donor car together with the bc unit from the donor car what else would I need to do.would I also need to change the instrument panel to get the correct mileage ,would my central locking still be functional .the scrappie has the donor vehicles ignition key,as just mentioned, can I get away with just replacing bc unit,engine ecu,and ign on my car with the ones from the donor car.or will I need to do more .:bang:

Cheers

 

[Ziggy122]

Punto's are NOT known for ECU Speedo related faults

What have you actually tackled? what have you tried so far

Ziggy

 

[benny279]

Right, in order for this to be sucessful swap over you will need from the donor car:

1) Engine ECU
2) Cabin Fusebox
3) Ignition Barrel
4) Lockset
5) Key

In terms of your central locking working ,you will have to swap over your lock barrels on the doors, which is straight forward anyway!

Other than that, no you don't have to change anything else, as the Engine ECU, Cabin Fusebox ,. Ignition Barrel and Key are all married to each other, one of those things missing and you'll won't be able to start the car, as immobilizer will be activated to prevent you starting the car.

Benny

 

[fingers99]

I'm fairly sure this will either be an issue with the speed sensor or the wiring to and from it, rather than the ECU.

As Ziggy says, what have you done so far?

 

[Ziggy122]

If my car ever gets locks broken into im going down the route of just Locks and keys copied onto a blank key set and swapping the Transponder over (like Atom did) in a guide

But i dont think the ECU is the key here

There is going to be a faulty sensor or a failed dash here

Ziggy

 

[benny279]

I agree with everyone above, I'd put my money on it being dodgy speed sensor, can't say ive heard an ecu cause such issue

 

[Cibo]

Hi ziggy
the history is in my previous thread( bout 3 was ago) I have a water damaged bc unit due to suspected flood damage so I've changed VSS and cleaned loom contacts to the VSS .Also changed fuse box with correct numbered replacement,retained original bc unit,checked all the main earthing points and cleaned up each individual plug sockets (the plugs that fit onto the pins on the fuse box and mother board) as there's no evidence of water level getting higher than about half way up the fuse box I've left that stuff alone but there are corroded pins on the bc unit hence ecus replacement cheered for your help

 

[Cibo]

Thanks everyone
If I go done the exchange root can't I just use my original key for the door locks or will that disable cental locking in other words have 2 keys 1 for ign and another for the doors

 

[Cibo]

Thanks everyone
If I go done the exchange root can't I just use my original key for the door locks or will that disable cental locking in other words have 2 keys 1 for ign and another for the doors:bang:

 

[benny279]

Thanks everyone
If I go done the exchange root can't I just use my original key for the door locks or will that disable cental locking in other words have 2 keys 1 for ign and another for the doors:bang:

That should be ok, always worth a try.

Benny

 

[Ziggy122]

So there are corroded pins on the ECU

A little bit of corrosion and your willing to spend money on donor ecu's....

The Engine ECU is pips to remove
Airbox off
undo the 2x self lever connectors and pull out way
Undo the 2x allen keys holding it all in place

With the ecu on a table, carefully using something like a nail file board or even a small screwdriver with some sand paper on it

once pins are cleaned, refit in reverse
a spray with electrical cleaner will help afterwards

I'd try any cheap trick to make something work! a mechanic would do so!

Ziggy

 

[benny279]

Ziggy122 Just like me until I deemed the engine knacked tried everything even your suggestions, so I agree OP try eays methods .

 

[Cibo]

Hi ziggy
It's the pins on the body control unit that are showing signs of corrosion not the engine ecu,
Where the pins, come out from the motherboard they then enter the plastic socket housing which is the bit you plug the loom into and block c which is to the right of the diagnostics socket is the one that I think the speedo ect has its own pins. As you look at the fuse box you will see a blue plug at the bottom on the far right so that's the one I'm talking about. Trouble is there's very little space between the mother board and the plastic socket housing and there's 40 pins so getting some thing in there is difficult let alone being able to see anything.
I lost the speedo again and the steering warning came on and when you leave the car overnight it normally resolves itself but after 10 miles or so I lose it again,however this morning the steering light was still on and no speedo so I disconnected the brown plug to the fuse box then the blue plug to the body control unit and after reconnecting them hey presto every thing working fine. I wonder if I could get anyone out there to replace the pins on the motherboard?if indeed that's the prob Cheers

 

[flisko]

Right, in order for this to be sucessful swap over you will need from the donor car:

1) Engine ECU
2) Cabin Fusebox
3) Ignition Barrel
4) Lockset
5) Key

In terms of your central locking working ,you will have to swap over your lock barrels on the doors, which is straight forward anyway!

Other than that, no you don't have to change anything else, as the Engine ECU, Cabin Fusebox ,. Ignition Barrel and Key are all married to each other, one of those things missing and you'll won't be able to start the car, as immobilizer will be activated to prevent you starting the car.

Benny

this guy is banned now but i still wanna know if its rly needed to change all that if you find engine ecu from same model with same specs as your car, will it work?

 

[oXRUSSXo]

this guy is banned now but i still wanna know if its rly needed to change all that if you find engine ecu from same model with same specs as your car, will it work?

Hi yes it is otherwise you will have the immobiliser on. So you have to swap everything and use the key from donor