Connector A

HITACHI SYSTEM CONTROL UNIT PIN-OUT

* Short circuited at pin 9 for versions without climate control

Connector A

1. Operation of injector for cylinder 1
2. N.C.
3. Operation of injector for cylinder 2
4. Pump relay operation
5. Operation of injector for cylinder 3
6. Negative for charcoal filter solenoid valve
7. Earth
8. Earth
9. Negative for engine idle adjustment solenoid valve
10. Operation of injector for cylinder 4
11. Positive for engine idle adjustment solenoid valve
12. Control unit supply
13. Climate control compressor relay feed (if fitted)
14. N.C.
15. N.C.
16. Earth

Connector B

1. Operation of coil for cylinder 1
2. Operation of coil for cylinder 3
3. Operation of rev counter
4. N.C.
5. N.C.
6. Earth
7. Operation of coil for cylinder 3
8. Operation of coil for cylinder 4
9. Operation of electric fan low speed relay
10. Operation of electric fan high speed relay *
11. Operation of system failure light
12. Earth

Connector C

1. N.C.
2. Positive for air flow meter
3. Positive for coolant temperature sensor
4. Positive for Lambda sensor
5. Signal for three stage pressure switch (if fitted)
6. N.C.
7. N.C.
8. Connection with FIAT CODE
9. Positive for detonation sensor
10. Negative for air flow meter
11. Line K
12. N.C.
13. Signal for butterfly position sensor
14. Negative for lambda sensor
15. N.C.
16. Signal for engaging compressor (if fitted)
17. A/V signal from ignition switch (+50)
18. N.C.
19. Earth for detonation sensor
20. Negative for coolant temperature and butterfly position

Connector D

1. Positive for engine rpm sensor
2. Positive for engine timing sensor
3. Earth for engine rpm sensor
4. Signal for vehicle speed sensor
5. Positive for butterfly position sensor
6. N.C.
7. Control unit supply
8. Earth
9. Negative for engine rpm sensor
10. Negative for engine timing sensor
11. N.C.
12. Calibration selection
13. Trim level selection (to earth for versions without climate control)
14. Control unit supply
15. Control unit supply
16. Earth