Electronic control (page 2 of 2)

The engine management control unit M10 monitors and controls the entire electronic ignition and injection system.

The control unit M10 is supplied directly by the battery at pin 4 of connector A via the 20A fuse for B5 and the 7.5A fuse for B35. It is also supplied through the ignition switch, contact 15/54 at pin 17 of connector A. Line 15/54 is protected by the 7.5A fuse of B25.

The control unit M10 casing is connected to earth C13.

The general injection relay J10 coil is operated by means of an earth signal from pin 6 of connector A of M10, whilst it is supplied b the 15/54 line of the ignition switch H1 via the 7.5A fuse for B25.

When the control unit M10 operates the relay J10 the contact closes and the supply is distributed to the following components:

• Electric fuel pump N40 pin 4
• Ignition coil A30 pin 1
• Fuel injectors
• 15A fuse B40

Fuse B40, in turn, sends a supply to the following components:

• Lambda sensor K40 pin 4
• Lambda sensor 2 K39 pin 4
• Fuel vapour recovery solenoid valve L10 pin 1

The contact for relay J10 is supplied by the battery via the 20A fuse B5.

The instrument panel E50 is supplied by the ignition switch H1 line INT through the 10A fuse F22, pin 18 connector A and directly by the battery, pin 17, connector A via the 7.5A fuse B25 and the 15A fuse F15 of B1. The earth C20 is sent to pin 16, connector A of the panel E50.

The speedometer sensor K84 is supplied by the ignition switch H1 line INT via the 10A fuse F21 and is connected to earth C10. The sensor K84 signal is sent to the control unit M10 pin 24 connector A and to the instrument panel E50 pin 9 connector A.

Pin 7, connector A of panel E50 is connected directly to pin 33 connector A of the control unit M10.

Pin 13 of connector A of M10 is connected to the 'OBD failure' warning light via pin 12 connector B of the instrument panel E50. When there is a failure, the control unit M10 sends an earth signal, via pin 13, connector A, to light up the 'OBD failure' warning light.

The inertia switch IS0 is connected to the fuel pump N40 and to the instrument panel E50 pin 13, connector A; in the case of an impact, it interrupts the supply to the fuel pump N40 and sends a signal to the instrument panel E50 pin 13 connector A.

The control unit M10 is connected to the following devices via the following pins:

• Pins 11, 22 and 32 connector A for supplying and receiving the signal from the Lambda sensor on the composition of the air/fuel mixture. The wiring is shielded.
• Pins 1, 21 and 31, connector A for supplying and receiving the signal from the Lambda sensor 2 K39. The wiring is shielded.
• Pin 7 connector A for receiving the signal from the Code control unit M20 pin 6.
• Pin 16, connector A for carrying out the diagnosis through the multiple diagnostic coupling pin 7
• Pin 35, connector A for receiving the signal from the electric steering control unit M86 pin 10
• Pin 26 connector B for supplying the fuel vapour recovery solenoid valve L10. It allows fuel vapours to pass through to the engine intake, where they join the mixture entering the combustion chamber. The valve L10 is opened by the control unit when the engine is loaded.
• Pins 13 and 22, connector B for receiving the signals from the integrated air temperature sensor K43; the sensor provides the control unit with a signal proportional to the tempreature of the air drawn in by the manifold. The wiring is shielded.
• Pin 29 of connector B carries the earth to sensors K43 and K45.
• Pin 14 of connector B supplies sensor K43.
• Pin 5 of connector B receives the signal from the coolant temperature sensor K45; The sensor provides the control unit with a signal proportional to the temperature of the engine coolant.
• Pins 25 and 35 receive the signal from the rpm sensor K46. The wiring is shielded.
• Pins 20, 24 and 32 of connector B receive the signal from the timing sensor K47; The control unit uses the timing sensor to recognize the injector and the ignition coil to operate. The wiring is shielded.
• Pin 3 of connector B receives the signal from the throttle position sensor K56; The sensor uses a potentiometer to produce a signal proportional to the opening of the throttle.
• Pins 6 and 15 of connector B receive the signal from the detonation sensor K50.
• Pins 27, 28, 36 and 37 supply the injectors N70 for the 4th, 1st, 2nd and 3rd cylinders, respectively.
• Pins 10 and 32 of connector B supply the ignition coils A30; The control unit controls the primary coil windings A30 through the earth signals, whilst the secondary winding sends the impulse to the spark plugs.
• Pins 9, 17, 18 and 19 transmit the idle actuator N74 signal; it consists of a stepping motor which controls the opening of the by-pass port.