[softlad]

Has anyone got any ideas where the ECU for a MK 3 golf TDi will be.
Another US forum says it should be just below the front windscreen next to the ventilation intake filter....Not there.
Someone else suggested under the rear seat...... Not there ABS control unit is but not ECU.

So as yet I have not managed to find it any suggestions.

 

[chittychittybangbang]

At the top of the forum, there is a long list of how tos specific to each forum. There is also a general faq called 1000q.



The ECU is under the front windscreen, see here.

Here is a how to article with pictures showing the ECU.
http://www.myturbodiesel.com/1000q_how_to/a3b4/ecuhosechip.htm

 

[softlad]

Read that long before I started looking, to be prepared and all that.
The ECU maybe there on US models but mine is a Japanese inport to New Zealand and it definatly is not in that position next to the vent filter ther is a huge empty space?????

 

[diesel guy]

Ah, that complicates things, I don't know. Maybe it's reversed and on the other side?

Try checking under the passenger's floorboard where they rest their feet, could it be under the wood floor? Maybe under the dashboard or near the relay panel under the steering wheel. It should definitely be near the firewall area near the end of the wiring harness.

Try followng the wiring harness and see where it ends, the ECU should be there.

 

[diesel guy]

here is a pic of a UK right hand drive passat with 1z engine. The ecu is marked #2 just out of frame, underneath the plastic, it should be on the other side as left hand drive cars.

 

[softlad]

Thats where I looked but there is just an empty void.
It's and AAZ engine and looking at your photo the 2 heater hoses that go through the bulkhead between nos 4 & 2 there is a vacuum hose that goes through there which is the one I'm assuming goes to the ecu it comes from where i see you have the blue sylican hose, and as I have changed all the others and still under powered I want to sort this on but after removing lower dash trim have discovered very little????

 

[chittychittybangbang]

Ah...if it's an AAZ, you have no ecu for engine control.

I don't know too much about the pre-TDIs but some areas that I would check:

First, the cold advance on the injection pump. Throttle cable adjustment.

here is another forum that knows a lot about the AAZ.

http://www.vwdiesel.net/phpBB/index.php

 

[softlad]

Now I'm slightly confused?
If my golf can be linked to VagCom surely that is the electronic brain of the car i.e. ECU?

 

[chittychittybangbang]

Okay, here's the way to tell for sure. Look at the pic above, does the injection pump look like the one above? If it doesn't and has cables coming out of it, then you have an AAZ.

I was mistaken though, the AAZ does have an ECU but it has very little to do with engine control. It's just a fancy glow plug relay timer and controls the injection start positioner. This retards the timing at low rpm. This is just what I read and I don't know what it looks like and where it is., the vw diesel.net forum knows a lot more about the AAZ pre-TDI engines.

 

[diesel guy]

If you find it, let us know where it is.

 

[chittychittybangbang]

If it's not a large ECU it could be hard to see too. I wonder if it just looks like a relay box in this car. I don't know much about the pre-TDIs so I hope he got a better answer at vwdiesel net.