Fitting an ecu.

[Matt]

If I unplug my current ecu. Without engine running, will I be able to plug it back in.
Is my ecu locked to my car?
I have another unlocked ecu to put on and try, but don't want to take mine off if I can't connect it again

[Foxy-jim]

When I was talking to my mate abou swapping engines. He said if I get a vtr ecu to run the vtr engine we can just plug it straight in a play. But we would lose the use of te immobiliser.

[Niall]

Yes you can Matt. Just don't unplug it when the car is running. I have heard some horror stories with this and people have wrecked most of the control units in their cars!

[Matt]

so disconnect battery
just unplug the ecu with the car off.
connect new ecu
connect battery
start her up?

[Niall]

Is the new ecu unlocked? If not you will also need the black dash module and chip from the key

But yes that's how you do it

[Matt]

yeah supposedly its unlocked. will anything break if i put it on and its not unlocked?

[Niall]

No it just won't start. Why are you putting an unlocked one on there? Yours buggered?

[Matt]

nope not bugered. bought an unlocked xsi ecu with remap

[Niall]

Fair enough. Plug it in and try it!

[Matt]

Will do tomorrow. To wet today, electrics ate bad enough

[Niall]

Will do tomorrow. To wet today, electrics ate bad enough

It's a 30 second job you homo!

[Gunge]

Is the ecu you've bought an open unlocked or a pro unlocked ?

I.E open unlocked is when the ecu is disconnected with ignition switched on or engine running leaving the immobiliser in an open state

pro unlock means the ecu has the immobiliser curcuit removed

this will effect how you connect the ecu, with the pro its just staight foward fit on, but an open needs you to remove wires on you car so your car doesnt send an incorect immobiliser signal to the ecu making it a locked ecu

[Matt]

It was removed with the ignition/ engine on. How do I connect it gunge?

[Gunge]

The way i do it (many people do it differently) disconect battery, remove the small engine loom plug located on the passenger inner wing, strip back the plastic so you can read the numbers on the wires, locate wires 820,821 & 822 cut all three and tape them up (making sure they will never touch) then connect the ECU connect battery and turn key

These 3 wires are what carries the signal from the transopnder to the ecu to tell it to either lock or unlock, the way the ecu has been removed means it hasnt recieved the 'lock' signal so you need to prevent it from revieving any signal as it will lock and only the original transponder will unlock it again

[Foxy-jim]

Need to do this when I swap my engine!

[Matt]

So if I connect the ecu up, it will lock, do I need the original Chip for the key?
I don't really want to get chopping wires when I don't know what I'm doing. If I cut those 3 wires will it stop the immobiliser working?

[Gunge]

Yes if you connect and not cut those wires it will lock needing the original chip/transponder set up

If you disconect your ecu with ignition on then after cutting wires you dont need to re connect them if there is a problem as your ecu will also be 'open'

[Matt]

Oh right okay, so remove my ecu with ignition on to be open,
Take off ecu
Turn off ignition
Disconnect battery
Remove loom, cut wires
Plug back in
Connect ecu
Connect battery
Turn on?

Is that right?

[Gunge]

yeah thats it after doing the wire cut if you wanted to go back to your original ecu its just swap over

[Matt]

Okay that's cool. So when I take my ecu of do I need car running or just ignition on?

I'll try this tomorrow

[taylonm]

Homo, is this oharas old ecu? If so we sold that to him. Its so simple. Plug and play just like a headlight bulb. Honestly! NO worries at all!

[Matt]

Yeah it's Oharas. Any idea what the map is? Gunna fit tomorrow and do this wiring thing as I havent got the original chip

[taylonm]

I cant remember off the top of my head but with a good filter and a decat I'm sure the cabby was running around 150bhp. We used to switch between ecu's depending on the drive.

[Matt]

Ahh right sweet, well on my xsi I'm runnin a gti inlet and a pipercross filter at the moment. Going to stick this on and give a good service

[Matt]

Anyone want to do this with me? I'm scared of cutting the loom and fudging it up

[Gunge]

Cant f*ck it up its an easy job

[Matt]

I just don't want to do something and lock both ecu's and both not work or something lol

[Gunge]

As long as you folllow steps you'll be fine

1 start car
2 with engine running remove ecu
3 cut the 3 wires 820,821 & 822
4 tape up the 6 cut ended wires
5 fit either ecu
6 turn key and here engine fire up

[Matt]

After step 2 turn engine off? Or will it cut out itself?

[taylonm]

Matt this ecu is unlocked, there's no immobiser on it.
To fit this on my bro's car we left the engine off, opened the bonnet, unclip old ecu dash it in the back seat, bosh in the new one. Start her up then boom! youre off! No problems all.