ECU Pin Out MAC-01
Main ECU connector pin out, 25 pins.

With the ECU removed from the car, and looking at release tang next to the pressure sensor port connection, Pin 1 is first pin on the bottom far left, Pins 2-13 follow on to the right, Pin 14 is first pin on the left, upper row, Pins 15-25 follow on the top row to the right.

german language english language
 1. GND  1. Ground
 2. Ladedruckanzeige im Digitalcockpit  2. Turbocharger pressure display in Digi dash
 3. Leerlaufschalter GND  3. Idle switch GND
 4. Hall Sensor GND  4. Hall Sender ground return
 5. nicht belegt  5. not used
 6. nicht belegt  6. not used
 7. Drehzahlmesser im Digitalcockpit  7. RPM display  in Digi dash
 8. nicht belegt  8. not used
 9. nicht belegt  9. not used
10.nicht belegt 10. not used
11. Drehzahl Sensor   (135 Impulse pro Kurbelwellenumdrehung) 11. RPM Sensor signal
12. Geber für Bezugsmarke GND (1 Impuls pro Kurbelwellenumdrehung, 60° vor OT, Zyl.1) 12. TDC Sensor signal GND
13. Geber für Bezugsmarke (1 Impuls pro Kurbelwellenumdrehung, 60° vor OT, Zyl.1) 13. TDC Sensor signal
14. Klemme 15 ( Ignition +12V) 14. Terminal 15 Ignition +12V
15. Leerlaufschalter  15. Idle Switch
16. Benzinpumpenrelay 16. Fuel Pump Relay control
17. TSZ Signal  (TranSistor Zündung) 17. Ignition Control Unit signal
18. Ansauglufttemp.sensor GND        18. Intake air temp sensor  GND      
19.Ansauglufttemp.sensor     19. Intake air temp sensor                   |
20. Hall Sensor Versorgung  +12V   20. Hall Sender + 12V  | 5Volt
21. nicht belegt 21. not used
22. Hall Sensor Timing signal (+5V, vor OT Zyl. 1) 22. Hall Sender timing signal
23. Drehzahl Sensor Abschirmung GND 23. RPM sensor shield GND
24. Drehzahl Sensor   (135 Impulse pro Kurbelwellenumdrehung) 24. RPM Sensor signal
25. Bezugsmarke Abschirmung GND 25. TDC Sensor Shield ground


Description measure between PINs Value
Air temperature sensor 18 and 19 between 18 (cold) and 33(warm) Ohm
Full throttle switch open circuit at  idle, 0 Ohm at full throttle
Idle Switch 15 and 3 0 Ohm at idle, open circuit at full throttle
Hall sender 4 and 20 min. 10V with ignition turned on
Hall sender timing 4 and 22 5V when the rotor of the hallsender is in front of the "window"



To check the speed sensor, remove the plug from the ecu and connect an
LED across terminals 11 and 24.Crank the engine over with the starter.
If the Led flickers on cranking the sensor AND wiring are good.

If it doesn't flicker,place an ohmmeter between terminals 11 and 23.
The reading should show "open".

Same across termonals 24 and 23 reading should show "open".

Next disconnect the speed sensor connector from the harness ( at the
firewall connector).Connect an ohmeter between terminal 23 and the
sensor connector female terminal on the left,(with the single keyway
on the harness on top). The reading should be 0 ohms.

If the wiring checks out and the led did not flicker, replace the
sensor.Thgere is no pin for the speed sensor. It "looks" at the
flywheel teeth.

Checking the reference sensor is similar.Connect the LED across
terminals 12 and 13 of the ecu connector.Crank the engine over, the led
should flicker. If it doesn't, check the wiring.

Put an ohmeter between terminals 12 and 25,reading should show "open".
 "      "         "         "      13 and 25,reading should show "open".

Put an ohmeter between terminal 25 and the reference sensor harness
connector,(pin on the left of the connector with the single keyway
on top). The reading should be 0 ohms (continuity).
If the wiring is good and the LED did not flicker,replace the sensor.

When you remove the sensor,along with it's mounting block,
you will see the hole in the bell housing that will allow you to
view the PIN in the flywheel (put the car in 5th gear on flat ground
and roll it 'till the pin appears in the window). Removing the plugs
makes this easier. The pin really doesn't have any relationship to
the TDC markings on the cam or the flywheel as far as using them to
find the pin.So you ahve to use the visual method to locate it.



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Copyright ©  Iain & Ralf