VR6 ECU question

[tug 0]

I had my VR in the garage for a diagnostics check a couple of weeks ago, and it turns out my ECU is faulty.

 

The serial number on my ECU is 021 906 258 AG. If I replace this with a Bosch Motronic 2.9 (non-immobiliser) ECU from a Golf VR6, and swap my chip over for the fuelling, etc., should that work?

 

I've done a search and had a good read of everything it came up with, but I'm just looking for a definitive yes or no answer! :)

 

Cheers,

 

Andrew.

[Rpmayne 0]

I can't remember the exact numbers but I've got an ECU from a Golf VR6 running on my Corrado. It worked both with the original chip and the Corrado one.

 

So I'm pretty sure yes.

[tug 0]

Excellent!

 

Thanks very much.

[tug 0]

Fitted an ECU from a Golf VR6 (021 906 258 BK) today. Car starts and ticks over fine, but misfires and is very hesitant up to about 2500rpm. After this it runs better, but still isn't right.

 

Is there something wrong with the ECU or is it just not compatible with my engine? Any ideas appreciated.

 

On the plus side, the car doesn't cut out with it fitted! :)

 

Thanks.

[corradovr6sc 0]

Is that with your corrado management chip fitted?

[tug 0]

The Golf ECU has the management chip soldered in, whereas my original Corrado one has a chip socket. Do you think that's the problem?

[corradovr6sc 0]

Could well be. The fueling on a Golf would be slightly different due to the smaller engine capacity and smaller intake manifold size etc.

[tug 0]

Rpmayne must have a different Golf VR6 ECU from mine, because from what he said he could swap the chips over.

 

It worked both with the original chip and the Corrado one.

 

Not sure what to do now. I could either get someone to solder in a socket so I can use my Corrado chip, or I could find an ECU that already has a socket fitted...

[corradovr6sc 0]

Some ecus have sockets but others don't, not sure why. I'd get a socket fitted. I got mine done by a computer guy. Cost about £5.

[tug 0]

I thought it would cost more than that!

 

I'll have a look into it, thanks.

[corradovr6sc 0]

Tuners want to charge a lot more than that (about £50-70) which is a rip off! It's only a five minute job for someone who's handy with a soldering iron.

[Rpmayne 0]

The original ECU from the Corrado had a soldered in chip, the ECU from the Golf was a socket type. £5.00 does sound cheap to change, and well worth it. Especially if you want to keep the original chip, cutting the legs off and unsoldering each one individually makes it alot easier.

 

As I say, I couldn't tell any difference with the Golf ECU and chip. Have you checked the ECU relay (can't remember the number), or the immobiliser part of your alarm? If the feed to the ECU is intermittent it could have been mis-diagnosed.

 

My problems started with the engine running fine, then randomly cutting out and refusing to restart. Had it on the diagnostics and it read no errors except it kept loosing comms. A new ECU later, took it to VW in desparation and they found that an immobiliser solder joint in the ECU feed had broken and was only held together sometimes by the heat shrink. VW originally wanted to change the ECU again (thinking the ECU was at fault), I told them it had already been done and then they had a rethink and found the connection. They also found it was a Golf ECU, which at the time I didn't know.

[Roger Blassberg 0]

You will also need to do a Basic Settings to the ECU using Vag-Com or VAG1551.

 

Best wishes

 

RB

[tug 0]

You will also need to do a Basic Settings to the ECU using Vag-Com or VAG1551.

 

Would not doing this make the car run like a bag of spanners?! I expected it to be a little bit off with the Golf ECU fitted, but it was nearly undriveable.

 

I've got someone who's going to fit a chip socket for me, so I'll see what the car's like with the Corrado management chip fitted.

[Allan 0]

How do you remove the ECU from the car??

 

I'm gonna get mine Chip'ed but not sure how to remove it.. People says that I schould remove the plastic cover under the front screen.. but don't know how to do this..

 

I'd really appriciate if anyone had pictures or some serious info about this..

 

the car is af '95 Corrado vr6...

 

Please help..

[Supercharged 2]

Yeah, you need to remove the plastic mesh - there is a kind of plastic clip that slides to release it then you will have room to get the ECU out

[Kevin Bacon 5]

It's easy. You just undo the 10mm nut holding the bracket to the scuttle and then wiggle it out!

[Trig 0]

It's really easy, the plastic cover under the right side of the windscreen (looking towards the rear) just pulls off. Then it is a case of sliding back a plastic release tab then pulling away the plug.

[RW1 0]

How do you remove the ECU from the car??

 

Disconnect the battery earth pole. make safe.

Lift the rubber seal forward of the plastic splash sheild. The lift the splash up and pull the ECU connector lock forwards. The connector will almost fall off. Now locate on the base plate moun the holding nut and remove, Shove the ECU side ways of the locating mouts for the base carrier plate. ECU should now twist out from under the winscreen.

 

.

[Allan 0]

But the problem is, that I cant get the ECU out from there.. I can get it loose.. but I have tried to move it in all directions to get it out... not enough room at all..

 

It's killing me... I even looked in the Corrado Official Repair manual from bentley... but the only thing they left out is the thing about the ECU... Damn..

 

Can anyone post some pictures about it??

 

Does it have anything to do with it, that my car is LHD?? '

 

 

Please help..

[RW1 0]

Does it have anything to do with it, that my car is LHD?? '

 

No.

 

Has the car had an accident at any time on that side. May have bent the bottom scuttle panel upwards. So the gap is narrower under the windscreen is narrower.

 

Try taking out the air intake cover over the cabin fan and move it towards the outer side.

 

.

[Allan 0]

Hey.. I finally got the ECU out of there.. pretty easy with the "air-vent" removed... :wink: :oops:

 

Well you learn every day...

 

 

Now to my next question - The number on the ecu is : VW 021 906 258 CP

 

Bosch - Ø 261 203 564/565

 

Any idea of what engine that box is for?? Previous owner of my car had an 2.8l engine installed because the original engine was damaged bad... now I have fitted a new 2.9 ABV engine in it... But not shure what the box is for.. 2.8 or 2.9... ??

[RW1 0]

The ECU is for a key immobilised version of the VR6 2.9ltr "ABV" engine fitted to October'94 - June '95 Corrado and the 4wd Mk3 Golf 2.9ltr VR6.

 

.

[tug 0]

Had to buy another replacement ECU after the first one was wrecked by some muppet trying to solder in a chip socket for me.

 

Code on this one is 021 906 258 AF and it works a treat! No hesitation, no flat spots, and more importantly...no stalling! :D