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MAC-12 ECU wiring

Interesting list. I added further descriptions from the
MAC-11B/C in parantheses.

Audi quattro - MB engine (MAC-12) ECU wiring

The  ECU is connected to the wiring harness via a  latch-
and-swing  connector.   With the  ECU  removed  from  the
vehicle,  the wiring harness connector should  be  viewed
with  the  plastic prongs on the right and  the  locating
lugs  along  the side of the connector at the  top.   The
upper  left pin is Pin 1, with numbering proceeding along
the connector to Pin 18 at the top right.  The bottom row
is  also numbered from left to right, from Pin 19 to  Pin

1.        Blue/White         Cold Start Valve (N17)
2.        Brown/Yellow       Chassis (gnd attached to ign coil)
3.                                     (carbon canister shutoff solenoid)
4.                                     (from decel shutoff valve)
5.        Brown/Yellow       Chassis (n/u on mac-11)
6.                                     (auto tranny input, open for manual)
7.        Mauve              Idle  Stabiliser (J142), Oil
                             Pressure Warning Controller
                            (to dash tachometer)
8.        Blue/Black         Frequency  valve  (N7), T35/3m (o2 freq valve)
9.        Brown/Red          Chassis
10.       Blue               Coolant Temperature (G62 - side
                             of block)
11.       Blue               Engine RPM Sensor (G28) (-)
12.       Mauve              Ignition Timing Sensor (G4) (-)
13.       Red                Ignition Timing Sensor (G4) (+)
14.       Blue/White         Electronic Thermoswitch (F76) (overheat switch input)
15.       Brown              Knock Sensor (G61)
16.       White              Knock Sensor (G61)
          Brown              (shield for above)
17.                               ( to  digital boost pressure gauge)
18.       Brown/Yellow       Chassis
19.       Green/Yellow       Wastegate Control Valve (N75)
20.       Grey               Idle Switch (F60), Idle
                             Stabiliser (J142)
21.       Brown/Red          Fuel Pump Relay (J17)
22.       Green/White        Electronic   Ignition
                             Power Stage (N70)
23.       Brown              Inlet Air Temperature Sensor (G42)
          Brown/Red          Hall Sensor (G40)
24.       Blue               Hall Sensor (G40) (intake air temp sensor)
25.       Red/Black          Hall Sensor (G40)
26.       White              Full Load Switch (F81) (full throttle switch)
27.       Green              Hall Sensor (G40)
28.       Brown              Shielding for 11, 12, 13, 29
29.       Grey               Engine RPM Sensor (G28) (+)
30.                              (o2 sensor)
31.       Black/White  (engine knock sensor/diagnostic light)
32.                              (brake light switch, used for auto tranny)
33.                             (o2 sensor)
34.       Brown/Yellow       Chassis (California code wire, open for 49 states)
35.       Black/Red          Power via Fuse (S34, 10A) (15 power)

Very similar to the MAC-11B/C ECU pinouts. One observation, it
seems that your car has only 1 knock sensor, not the 2 you 
thought you had. 15/16 are used for the single knock sensor

Notable differences
 lack of o2 sensor
 still has o2 freq valve control, probably uses duty cycle lookup
 table in the ECU.
 INteresting that the CA code wire is grounded in you app.

Which turbo is installed on the MB K26 or K24? Also what
the boost pressure?
Dave Lawson
83 ur-q, mac-11b, 1.8bar, k26 clipper ship