Poorly engine

R

Rem

New Member
Hi all. I love my A2, Lexie and want her to last as long as possible. My other car is a 40 year old 924! Where do I find her ECU, what does it look like and how do I ckean it? Cheers, Rachel
 
Hi Rachel

The ECU is under the passenger floor. Lift up the front carpet and there is a metal panel with 3 twist clips. The ECU and CCCU are under there in a black plastic cradle.

Can I ask what leads you to believe that you need to clean your ECU? It is an electrical component stored in a clean dry oart of the car.
 
A2Steve said:
Hi Rachel

The ECU is under the passenger floor. Lift up the front carpet and there is a metal panel with 3 twist clips. The ECU and CCCU are under there in a black plastic cradle.

Can I ask what leads you to believe that you need to clean your ECU? It is an electrical component stored in a clean dry oart of the car.
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Thankyou and just from googling the problem it seemed to be the next thing to try after a change of coils. R
 
Hi Rachel,

Welcome to A2OC. Sorry to hear that your A2 is a little poorly.
Could you please describe to the community the problems/symptoms that you’re experiencing? Has a diagnostic scan been performed?

I imagine that the advice you’ve received is to clean the ECU’s electrical connections rather than the ECU itself. I’m sure we’ll all agree that a few Dettol wipes across the ECU is going to achieve absolutely nothing.
In many other cars, the ECU is held under the bonnet. In the A2, it’s held in a dedicated electronics compartment under the passenger’s feet, where it’s largely protected. Furthermore, the electrical connectors are protected by rubberised seals. Having disconnected literally hundreds of A2 ECUs over many years, I have never seen anything but factory-standard cleanliness here.

Cheers,

Tom
 
You could ask here what you asked Google.

Have you scanned it with VCDS? If you're in this for the long term, buy a cable for it. All cars made this century first thing to do is to talk to it and let it tell you what it's not happy about.

Second is, have you checked the earth cable, this is the second of two most common things suggested. In the same way the ECU will tell you what's wrong, all the stuff it talks too needs a good ground and a decent voltage coming from the battery so they don't grumble to the ECU saying 'implausible signal' and voltage 'out of range'. My A2 and TT grumble less once I'd sorted a new battery (and alternator for the A2) and a new earth cable.

TBH, I think your 'new member' to 'member' forum status only changes when someone has replied with 'Scan with VCDS' and 'Check the earth' ;):p
 
Thanks for the warm welcome ? it started with an occasional loss of power. Now the engine light is on and there is a constant loss of power particularly acceleration. When the engine light starts flashing she judders and jolts and it's like driving a tractor! R
 
So, I'd move on to getting it scanned.

There's a free scan register of hopefully a nearby member who can scan it for you, and see my suggestion of buying a VCDS cable (the software is free) it really does pay for itself IMO. Trouble is it's an always an additional expense when you're looking to get things fixed.

So the ECU is the right place to look, just not physically, you use the OBD-II plug/socket underneath the dash.

As said above the ECU is quite dry and cosy and I'm sure I'd have read more stories about mice making it their home if there was a danger of ingress :)
 
Rem said:
Thanks for the warm welcome ? it started with an occasional loss of power. Now the engine light is on and there is a constant loss of power particularly acceleration. When the engine light starts flashing she judders and jolts and it's like driving a tractor! R
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Welcome from me too!
Maybe I missed it, what engine is your A2 please, I'm guessing it might be a 1.6 FSI?
Mac.
 
4markowen said:
You could ask here what you asked Google.

Have you scanned it with VCDS? If you're in this for the long term, buy a cable for it. All cars made this century first thing to do is to talk to it and let it tell you what it's not happy about.

Second is, have you checked the earth cable, this is the second of two most common things suggested. In the same way the ECU will tell you what's wrong, all the stuff it talks too needs a good ground and a decent voltage coming from the battery so they don't grumble to the ECU saying 'implausible signal' and voltage 'out of range'. My A2 and TT grumble less once I'd sorted a new battery (and alternator for the A2) and a new earth cable.

TBH, I think your 'new member' to 'member' forum status only changes when someone has replied with 'Scan with VCDS' and 'Check the earth' ;):p
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Thanks for that funnily enough having the same issues with earthing out with my 924 ? R
 
Rem said:
Um where would I find the earth cable....
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Behind the nearside headlight, which you need to remove (2 bolts, one connector). Long extension required to get to the bolt head along the chassis leg and under the AC pipes if you have AC. Clean up the mating faces to bare metal. The earth strap has also been known to look OK from the outside but be corroded right through inside its plastic coating, so once disconnected give it a good tug to check if you need a new one.

You can see the bolt location in this photo but the bolt head had sheared off. Further photos are here (and see the preceding posts in that thread for better explanation).

1629376872132.jpeg
 
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Welcome to the forum.
I had similar driving issues with my Fsi, replaced the rusty washer behind the passenger headlight eart cable & problem solved.
 
Ami said:
Welcome to the forum.
I had similar driving issues with my Fsi, replaced the rusty washer behind the passenger headlight eart cable & problem solved.
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Thankyou and fingers crossed! She is so easy to drive I would hate to give up ?
 
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Rem said:
Thanks for the warm welcome ? it started with an occasional loss of power. Now the engine light is on and there is a constant loss of power particularly acceleration. When the engine light starts flashing she judders and jolts and it's like driving a tractor! R
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Sounds to me like a misfire, running on less than 4 cylinders - this is the exact symptom we had with ours. From experience, I would bet on needing a replacement coil, and depending on how well maintained the rest of the engine is, possibly plugs and leads could help as well.

In our case, there had always been a slightly rough idle and light came on with a failed EGR. Replaced EGR and cleaned / replaced the throttle body. Noticed the plugs were non-identical and looked grotty, so replaced them and the leads. Fitted a set of refurbished injectors, but still occasional hesitation around 1600rpm, but the car ran o.k for the next 6 months or so. Then my other half noted that on days when it was really damp that it would run rough and the light come on - but I was able to turn the light off on the drive and it would run o.k at home, until it stopped running properly at all (down to 3 and then 2 cylinders, being totally undriveable and very rough) - and I eventually realised that the coil casing was cracked and insulation all failed on the back of the casing. New Bosch coil sorted it all out and we've only had sporadic lights on since due to occasional crankcase pressure sensor errors that immediately went away.

If a scan tells you it is misfires then the immediate next step would be to undo the coil (I think it is an allen key job to take it off) and have a good look at the casing on all sides. It is in a hot location, and will have been for nearly 20 years, so unsurprising that it starts to fail eventually.
 
Oh my goodness me and my hubby finally got around to investigating the earth cable. Thankyou so much for photo and description of how to locate it. The nut was completely coroded. We sanded it and the washer- Lexie is cured! Hopefully and fingers crossed anyway ?
She now needs a new wiper unit where should we try?
Thanks!
 
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