New to forum and have a fun issue with my d2

[TheDoshMonster]

Hello everyone. Im from the US and this is my first audi. i have a 97 with the 4.2 and the winter edition package.

Current issue is it wont start. i got fuel to the rails and spark but with Motronic current supply relay (J271) in place i cant get any fuel to come out of the injectors. i have just under 12 (11.9) volts on positions 30 and 86. when i jumper with a wire with positions 30&87 ill get some occational fires. Is this a common issue people have seen before? any help is appreciated.

[Ronin]

how much fuel in the tank do you have?
Is the fuel pump the original vdo/continental part?
Is the car Automatic? if so it could also be a faulty F125 gearbox positioner. I've had mine at a jet wash and it just wouldn't crank.
There's also a fuel filter which everyone neglects located basically under the rear door of the passenger (lhd) which may be worth checking

[TheDoshMonster]

I just got a hold of this and supposedly the car was sitting for roughly 7 months due to the driver losing his license from old age.

List of things that have been replace (sorry i should have listed this before hand)
fuel pump,fuel pump relay, coil packs, spark plugs, Motronic current supply relay (J271) (granted i dont have a new OEM one but i get the same result with the old and the new), Battery, and the ICMS. I'm getting a laptop tomorrow so i can put vagcom on it and run its software.

I was currious if it had to do something with an imobilizer (i do not have the light on the dash with a key inside of a yellow light) or key program after replacing the battery, the old battery was from 2015 and didnt make it through this winter so it was pretty dead.

The car is automatic, the tank says just under half full but i don't really have a way to tell if the sensor is broken i just know there's plenty of pressure and fuel at the rail, i didn't know about the fuel filter. and I'm not 100% if the fuel pump is oem or not i can check. That's the one part i had a buddy install while i was out of town for work. I have not checked if f125 is faulty is there a way to test that before buying another relay?

[Ronin]

Yes, remove relay 204 from the relay box under drivers feet (it's at the very top of it) and bypass it like below:

Screenshot_2025-02-03-16-05-30-18_a23b203fd3aafc6dcb84e438dda678b6.jpg

[TheDoshMonster]

i cant find it and all i have now is some broken mounts for the interior plastics haha.like i genuinely dont see any relay locations and i was able to get the underside flap off where your shins would be at and still dont see any relays above. I have a Left hand drive model as im in the US, if its still drivers side how do i get to it??? and is there a better description than relay 204? i guess is there a video or some sort of way to know how to get up to them? i havent found anything online.

[Ronin]

The relay will literally have 204 written on top of it and will be located at the very top row.
Impossible to miss.

This is the relay box, it will have a piece of MDF covering it:

Screenshot_2025-02-04-08-54-37-73_40deb401b9ffe8e1df2f1cc5ba480b12.jpg

[MikkiJayne]

Devin yes? I've written two detailed replies to this thread and failed to hit 'submit' on either of them sorry!

Some logic:

If the engine has spark then it must be spinning on the starter yes? Also it must have a crank signal otherwise it wouldn't make sparks, so we can rule out the F125, the starter interlock relay, the motronic relay, and the crank sensor.

If it has fuel pressure at the rail (like 45-60psi of it, not just a dribble), then the fuel pump is working and therefore the relay must also be working. The fuel pump relay (the blue one in the pic above) has a number of outputs, but its rare for the relay to fail at all, let alone one of the secondary outputs, so I'm confident we can rule that out too. Whether you have a correct fuel pump is a question for later.

Having checked the wiring diagrams, the motronic relay is doing the switching for the injectors, via fuse 'S116' which is a blue 15A. This lives in the electronics box in the plenum next to the ECU. Even if this fuse isn't blown, its quite common for the contacts in the fuse holder to get corroded due to moisture ingress, which will prevent power from getting any further as surely as no fuse at all. I would suggest cleaning the contacts with emery paper and WD40, and then verify you have 12V at the fuseholder while cranking. Replace all the fuses in that block and give it another go

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pic2.JPG

[TheDoshMonster]

@ronin ahh i think i found the location your talking about it is on the passenger side for me (see attached pictures) the yellow connector you had bridged doesnt exist in the same spot and found it but i have a purple relay with no number on it. i still tried it bridged with no change. there were two others with 204 on them i tried with them bridged with no change either.

IMG_2941.jpg

IMG_2940.jpg

IMG_2937.jpg

as for doing the connections in the plenuem box above i cleaned them and they look alright connection wise to me.

[Ronin]

Ok, in this case I suggest you follow MJ's instructions

[TheDoshMonster]

Alrighty ive finally got the computer and paid for the program so i could run a full diag. this is all the issues it seems to see. does this help at all with a better location for a possible fault in my wiring? or maybe something more specific not working right? all connection seem to be fine. could it have something to the ECM incorrectly coded? if so how do i correctly code it?



18010 - Power Supply Terminal 30: Voltage too Low
P1602 - 35-10 - - - Intermittent
18020 - Engine Control Module Incorrectly Coded
P1612 - 35-10 - - - Intermittent
17925 - Power Supply Relay for ECU (J271 or J363): Electrical Malfunction
P1517 - 35-00 - -
17609 - Fuel Injector for Cylinder 1 (N30): Electrical Malfunction
P1201 - 35-10 - - - Intermittent
17613 - Fuel Injector for Cylinder 5 (N83): Electrical Malfunction
P1205 - 35-10 - - - Intermittent
17612 - Fuel Injector for Cylinder 4 (N33): Electrical Malfunction
P1204 - 35-10 - - - Intermittent
17616 - Fuel Injector for Cylinder 8 (N86): Electrical Malfunction
P1208 - 35-10 - - - Intermittent
17817 - EVAP Purge Valve (N80): Electrical Malfunction
P1409 - 35-10 - - - Intermittent
17919 - Intake Manifold Valve (N156): Electrical Malfunction
P1511 - 35-10 - - - Intermittent
17917 - Idle Control Valve (N71): Electrical Malfunction
P1509 - 35-10 - - - Intermittent
16944 - System Voltage: Malfunction
P0560 - 35-10 - - - Intermittent
Readiness: N/A