[Es2] [urq] Wiring Harness

Martin Pajak martin at quattro.ca
Wed Apr 26 21:43:38 EDT 2006


All of the engine related plug on the S2 harness plug straight into the
Coupe/4kq fusebox.  Afterall it is the same fusebox as on S2/RS2.
Only the stuff for the trip computer, tach, temp gauge and cruise control
speed signal need to be connected into the wiring harness... even then most
of the car side plugs can be used and made to look factory.
Here are the notes on the engine wires that need to be plugged into the

3B ECU Pin Out Signal Description

1. Output stage for Ignition coil N70 (Green/White)
2. Coding Plug (Yellow/Black) 
3. Fuel Pump Relay J17, G6 (Brown/Green) Fuse Box "BS" (Green/purple) 
4. Idle Stabilizer N71 (Gray/Black)
5. Carbon Canister Frequency valve N80 (Black) 
6. Tachometer (Purple) DigiDash "T35/31" (Purple) 7/25 
7. Mass Air Flow Sensor G70 (Black/Gay)
8. Hall Sender, G40 (signal wire) (Green)
9. Open, not used
10. Ground (Brown/Yellow)
11. Knock Sensor #1 G61 (Black)
12. Hall sender, altitude sensor, etc. (+5V) supply (Red/Black)
13. Diagnostic plug (L wire) (Black/White) Diagnostic "T2a" 
14. Control Unit ground (Brown/Red)
15. Injector #3 control signal N32 (Brown/Green)
16. Injector #2 control signal N31 (Brown/Blue)
17. Injector #1 control signal N30 (Brown/Black)
18. Terminal 30 (+12V) supply, Fuse #26 (Red/White) Fuse Box "L30"
19. Control Unit ground (Brown/Yellow)
20. Open, not used
21. Open, not used
22. Diagnos. out (Gray/Brown) Diagnostic"T2b"DigiDash"T35/33"FuseBox"ILa"   
23. Wastegate Frequency valve N75 (Green/Yellow)
24. Control Unit ground (Brown/Red)
25. Mass Air Flow Sensor (+ pin 4) G70 (Blue/Purple)
26. Mass Air Flow Sensor (+ pin 2) G70 (White/Green)
27. Terminal #15 (Ignition +12V) (Black) Fuse Box "B15")
28. Oxygen Sensor G39 (green coax cable)
29. Knock Sensor #2 G66 (White)
30. Ground (Black/Purple)
31. Boost Pressure Gauge (Purple/White) DigiDash"T35/16"(Brown/white) 2/25 
32. Trip Computer (Blue/Black) DigiDash "T35/34" (White/Green, Green/White)
33. Open, not used
34. Injector #5control signal N83 (Brown/Red)
35. Injector #4 control signal N33 (Brown/White)
36. Multifunction temperature sensor F76 Pin R (Blue/Black)
37. Voltage Supply input (+12V, Fuse #28, Blue/Black) Fuse Box "87a"
38. Coding plug (Brown/Blue) 
39. Coding plug (White/Black) 
40. A/C Compressor (Green/Black)
41. Idle speed increase signal (A/C on) (Brown/Black)
42. Open, not used
43. Open, not used
44. Intake Air Temperature Sensor G42 (Blue)
45. Coolant Temperature Sensor G62 (Red/Green)
46. Altitude Sensor F96 (Gray)
47. Engine Speed Sensor G28 (Gray)
48. Ground for reference and speed sending units (shown as two wires, one
Red, one Blue)
49. Reference G4 (62 degree before TDC) sending unit (Purple)
50. Open, not used
51. Open, not used
52. Idle Switch F60 (Green/Purple)
53. Throttle Valve Potentiometer G69 (Gray/Blue)
54. Coding plug (Red/Yellow) 
55. Diagnostic plug (K wire) (Yellow/Blue) Diagnostic"T2a"  

Martin Pajak


1982 Audi Ur-quattro (50,000 mi) new project
1983 Audi Ur-quattro (85,000 mi) Concourse d'Elegance
1985 Audi Ur-quattro (212,000 km) Euro spec. import mit 3B :)
1987 Audi 4000s quattro (205,000 km) wintervagen mit 7A :)
1990 Audi V8 quattro (365,000 km) pipe and slippers

-----Original Message-----
From: Jack Walker [mailto:JackW at ihco.com] 
Sent: Wednesday, April 26, 2006 7:46 PM
To: seiche at shadetreesoftware.com
Cc: Martin Pajak; es2 at audifans.com; urq at audifans.com
Subject: RE: [Es2] [urq] Wiring Harness

Baby with the bath water, pretty good???

Wasn't something I had control over, before it was sitting in a scrap
yard, my original goal was the harness, the fuse box, the dash,
everything. But when it went to the scrap yard, I didn't have a lot of
options. They weren't even going to let me in the yard after it got
loaded into the dump box, until they asked for the title. Told them to
bring it back...or I would call the police and say it was stolen.

The major reason I went for the fuse box surround was the lip in the
under hood area that another fuse box could eventually go on top of
along with the butyl tape. I've got a fuse box and harness from a FWD
4000 and a bunch of dash parts...? There are a ton of 4000 CSQs around

Don't things like the Ur all the dash display-speedo, tach, wiring have
to be spliced into what ever harness I end up using, On the Lighting,
A/C, Starter, rear wiper, and the battery can't I use the Ur wiring?

Jack Walker
503) 419-4601  Direct Phone Line
503) 807-3807  Cellular Phone

-----Original Message-----
From: Steve Eiche [mailto:seiche at shadetreesoftware.com] 
Sent: Wednesday, April 26, 2006 5:22 PM
To: Jack Walker
Cc: Martin Pajak; es2 at audifans.com; urq at audifans.com
Subject: Re: [Es2] [urq] Wiring Harness

Well, you kind of threw away the baby with the bath water.  There is no 
need replace the area where the newer fusebox mounts.   The area is 
already properly shaped for the newer fuse box.  All you need to do is 
cut the hole for the housing and seal it with butyl tape (same stuff 
used by the factory).  It will be indistinguishable from the later fuse 
box setup.  You will want to remove the old fusebox bracket, and weld in

the two brackets for the relay panel, but that is all you need.  You 
should have saved the wiring and forgotten about the sheetmetal.  You 
will want CGT wiring for the rear harness(es if you have a rear wiper), 
as well as the control stalks, but 4kq harnesses will work for the 
rest.  Either way, you will have to make some changes, especially in the

lighting circuits, A/C, starter and battery no matter what you do.

As for the RS2 harness, yes, that will work much better than the S4/S6 
AAN harness.  I'm not sure where Martin gets his 99% from, but I have an

RS2 harness, and while the black connector with five wires that goes to 
the fuse box has them in the right places, and the fuses are easy to 
connect, but the other 19 are not plug-in compatible.

Steve Eiche
Shade Tree Software, LLC
http://www.shadetreesoftware.com   http://www.prodiag-hd.com
seiche at shadetreesoftware.com

Jack Walker wrote:

>Thanks Martin,
>You placed a 3B into the S2 harness, which is what the S2s came with,
>would I be better off with a RS2 in regard to the AAN motor?
>Was planning on getting the wiring harness out of the CGT, but after it
>sitting in my driveway for a while too long my wife decided to have it
>taken to her work where I could get the harness, fuse box, and anything
>else I wanted off. Didn't quite happen that way, got thrown, into a
>dumpster by a forklift and taken to a scrap yard.
>Hardly got the brake booster sleeve and the surrounding area of the
>box out with a torch, which I'll trim down to make the fuse box
>surround. But in cutting it out it turned most of the harness and the
>box to a smoldering mess of crap. 
>Jack Walker
>503) 419-4601  Direct Phone Line
>503) 807-3807  Cellular Phone
>-----Original Message-----
>From: Martin Pajak [mailto:martin at quattro.ca] 
>Sent: Wednesday, April 26, 2006 1:48 PM
>To: Jack Walker
>Cc: es2 at audifans.com; urq at audifans.com
>Subject: Re: [urq] Wiring Harness
>I used an S2 harness in my '85.. and 99% of wires just simply plug into
>the fusebox/original harness.. the trick here is to have a car with
>wiring and underhood fusebox.
>You can find an S2 wiring diagam at
>And RS2 is here:
>If you need some help I can scan my notes and send them your way.
>Actual wiring took me about half an hour.. but labling and preparation
>dictates how much time you actually spend under the dash with a trouble
>light.. :)
>Hope this helps

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