Right guys, need some help. Today, Me and Eddie noticed that my Mk2 1.8T is missing the barometric (altitude) sensor, and this was flagged up when plugged in. Now, I have this spare plug in my engine bay - ... Which i would have thought was for the sensor ? But upon looking on the net for one, it seems to be showing up sensors with a square plug ? Can anyone confirm if the barometric (altitude) sensor uses a rounded plug on the AGU's, and a part number to the correct sensor would be great too I want to try and get this sorted out next week. Thanks in advanced. Rich.
Right, I decided to google the part number printed on the connector plug. The majority of the results came up saying that this plug is used for the speed sensor. So now this has thrown a spanner in the works ...... I'm now confused why my ECU is throwing up faults codes regarding the Barometric (altitude) Sensor not plugged in, when there isn't any wiring or plugs for this ? The Barometric (altitude) Sensor uses a square plug like this - And a square plug like this is nowhere to be seen on the loom ?
Pt no for the sensor is 0 280 101 001 also 853 919 562 here are some pic of mine the wires, plug and sensor
Mate your a star, thanks for posting those pictures above I can now say that i definitely don't have this plug on my loom for some reason ? Now I've got to figure out why, and also how its wired in originally ? Where abouts does this plug's loom run off from Nathan ? Is it near the coilpack loom ?
See the above link for how the Barometric pressure sensor is wired Rich. The diagram on the right is just a zoomed in version of the one on the left. In either case, you are looking at sensor B121 on the image.
It runs across the bulk head in the main loom comes out roughly where the wiper motor is, same position as the mk4
Yeah I bought the ECU and wiring loom from a guy breaking an Audi A3 1.8T. The part number on the ECU is - 06a 906 018 CG. The loom is definitely an AGU one as it has all the early square'ish loom plugs throughout.
Thanks Lewis, appreciate that I can sort of make sense of it Lol. It's strange that this is missing from my loom though ? Cheers Nath. I'll have another look tomorrow and see if I can find anything. I can't recall seeing this though. Not looking forward to wiring it in
I have done some brief investigations and it appears both the altitude sensor (F96) and the cam sensor (G40) share the same power source of 5v on pin T80/62 of the M3.8.3 ECU. I have observed both sensors showing as faults. I would suggest checking the supply at the cam sensor at pin 1 to see if this 5v is present. If not, the connection at the ECU pin T80/62 needs to be checked and if 5v, find out why the cam sensor is not picking up the supply. Cam sensor fixed or replaced, tap the supply from T80/62 to pin 2 of F96, acquire ECU input at T80/61 to pin 1 of F96 and earth at pin. This should get rid of the 2 faults and allow a baseline for an engine re map. Diagram of how it is connected below.
Thanks mate, really appreciate the info above So, as we was seeing fault codes for both the cam position sensor and the Barometric pressure sensor, its down to them being related. I would never of guessed that ! Hopefully with a few hours spare during next week, I should be able to get to the bottom of this. Will keep this thread updated
Looks like something else is connected to the same point, on current track 63. Might be useful to know what that is.
Right then. I've been speaking to the electrical guru himself ( Rubjonny ) regarding the wiring for the sensor. The wiring colours to look for are - * Red / White * Purple / Red and * Brown / Blue Starting at ECU pin 61, i should be able to trace it and hopefully come across snipped wires or maybe a plug somewhere ? Will have a look tomorrow and report back.
Just checked mine, the loom for the Barometric sensor wiring comes out of the same "engine loom branch" as the ignition amp loom.
are there any other ecu (n/a 20v maybe?) which use same ecu plug and so similar loom but without the altitude sensor? maybe you have the wrong small ecu loom section? Had a quick look in elsa but couldnt find anything so not sure if this is the case. worst case if this is one of mine it should just unplug and you can swap on another AGU loom, just need to check the main loom connection to see if its a 10 or 14 pin plus possibly change the coolant temp sensor for a mk3/early mk4 if you have a mk3 4 pin coolant temp sensor. i may have put a resistor in the coolant temp wire so it works with a mk4 coolant temp sensor though if its one of my early ones...
Thanks Lewis Just popped round the lock up and found it, YAY I also managed to get hold of the sensor too, all working and tested for 5, so not bad at all. Next on the list is changing the cam position sensor. Can anyone confirm if the AGU and AUM use different cam position sensors ? Cheers.
Cheers Nathan I've got a couple spare laying around, so I'll pop one on and see if it clears the error code.
