Hi all, New member. Been scouring the internet looking for help and this forum seemed to come up trumps on a number of things. I am currently putting a 1.8T (AGU) engine into my T4, replacing the old tired 2.5TDi (AJT). I am hoping someone can help me as I am looking for a wiring diagram so I can convert my loom. I believe the engine I have is from a mk4 Golf (apparently the AGU wiring differed in the Golf to the Audi??), as above its an AGU, and if needs be I can try and get the engine number - if it hasnt disintergrated. Many thanks in advance.
what age is the T4? if it has the CE2 fusebox, you can use this: https://clubgti.com/forums/index.ph...install-faq-now-with-added-dieselness.267196/ only thing to note the later T4 CE2 fusebox has a couple oddities for the cluster wiring they have a single oil pressure switch (so only 1 switch to swap, keep old wire) and the speed/vss is moved to a different pin.
ok whats the engine code (or part number of ecu if unsure) but yeah its a ce2 fusebox probably, compare it to this: https://clubgti.com/forums/index.php?threads/fusebox-faq.219775/
ok just double checked, and its all the same as usual except you only need 1 oil switch from the old engine just swap that for the mk4 one and splice the t4 switch wire to the mk4 t14a pin job done
@rubjonny another question for you on this project. Loom is sorted and van is now running with a 20vt in, so thanks for your help with that. Now I need to change the dashclocks as my diesel ones redline at 5k. I was looking at mk4 golf GTi clocks, as thats what the engine came out of. The mk4 ran canbus though, so are there any clocks that would be a straight swap? Or is there an adaptor I can use so I can put in some clocks and they all work nicly, or am I asking too much??
you can use early mk4 clocks they ran rev counter and mpg over physical wires, only later ones were canbus. you could always run the canbus wires from your ecu to fusebox though you've managed all this so far what's 2 more wires tbh I'd rather get a set of clocks that are a straight fit will save a lot of hassle, not like the mk4 ones are all that special. think its mk3 clocks that fit the T4 right? maybe passat/corrado?
Mines the later T4 so the clocks are similar to the mk4 golf, or I thought they were (picture of the style of clocks I have below). I was looking at a set of mk4 clocks from a AUM. I believe the plugs are the same, but like I said, I'm unsure as to what will/wont work without additional work.
ah ok, carry on then. so you'll want early style clocks those will accept a rev counter pin rather than ne3ed it over can-bus. I believe the early clocks which take rev counter pin are all immo 2 and canbus type immo 3, but I might be wrong on that one
later agu ecu do have canbus wiring though, so its possible you could hook that up and have later type working. this thread covers everything anyway: https://www.uk-mkivs.net/threads/mk4-golf-and-bora-speedo-instrument-cluster.10689/
So, I'm going to swap the clocks over this weekend and hope for the best. One question I have is regarding the immobiliser. It has been coded out on the ECU, so when the new clocks in my understanding is that the immobiliser/key light will flash because the dash "won't recognise" the key. Now, again this is my understanding but I may well be wrong so please feel free to correct me, this won't stop the engine from starting and running, but is the flashing light something that can be coded out in VCDS/vagcom? Thanks for all your help.
You cant turn it off with vagcom but it can be done with different cable/software. Thing is, if you have the MK4 cluster you could have immo coded to cluster if you get a matched chip with the clocks
Right, I think its just going to be a case of "fit it and find out". I know the clocks are immo2 from that thread on uk-mkivs, and the one in my van should be immo2 as well. Is there a way to tell if the cluster is coded, and if it is, is there anything I can do, or will I need to find a complete car being broken and buy the clocks, keys and ecu?
So far as I know the key light will turn off adter a few seconds or so, you can always pull the led.off or put tape over it
So small update; Swapped clocks over, easy job although needed to swap the cowlings over as the T4 one has mountings on it. Plugged the new ones in and it lights up and rev counter works - Speedo should but yet to confirm. Temperature dial moves but hasn’t got to 90° yet, but I might need to take it on a long journey for it to warm up properly. Only issue I can see so far, is the fuel gauge. As I was coming to the workshop my fuel light came on, however the new dials are showing 3/4 full ♂️ I’m thinking these could be the reverse of the T4?? As for warning lights the dash looks very festive; airbag, brake pad sensor, washer fluid level and ABS light all on constantly on (Airbag, washer fluid and ABS need to be coded out as I’ve not got them on the van). Pad warning needs to be coded out as the previous owner cut the wires! Immobiliser and handbrake light constantly flashing - assuming handbrake is linked to immobiliser.
You can use vagcom to turn most of those lights off, the handbrake one may be low fluid or just down to the abs Not sure on fuel gauge, but you may be right it's flipped Vs mk4. I assume you can do the same.mod where you cut the wire from sender board and solder it to the other side, or possibly you could swap a MK4 fuel pump assembly into your tank?
Taken it for a drive, Speedo works however now have a massive ‘STOP’ in the digital display. It’s also saying oil pressure, now I know when we did the conversion the oil pressure switch wire was quite short so it may need extending. I also believe that the plug had the clip broken so it might not be on properly. Will have to look into that. Fuel gauge will probably become clear when I fill it up next.
Stop will be due to oil pressure warning, did you change the switch on the engine when it first went in
