AUTOMATIC TRANSMISSION - OPERATIONAL DESCRIPTION

2.2

The automatic transmission control unit M055 controls and regulates the entire gearbox management system.

The direct power supply (+30) reaches, via a line protected by fuse F18, engine compartment control unit B001, at pin 33 of connector A of automatic transmission control unit M055 and pin 9 of gear selector control unit M053.

An ignition-operated power supply (15/54) from the steering lock control unit reaches pins 22 and 31 of connector A of M055, at pin 22 of automatic transmission solenoid unit L050 and pin 1 of speed selector control unit M053 via a line protected by fuse F24 of engine compartment control unit B001.

The passenger side dashboard earth C020 is connected to pin 2 of speed selector control unit M053.

Left front earth C010 is connected at pins 23 and 32 of connector A of transmission control unit M055 and pin 21 of automatic transmission control unit L050.

Gear selector control unit M053, via pins 4 – 6, 7 – 5 and automatic transmission control unit M055, via pins 25 – 26, 35 – 36, communicate via the C-CAN network and interface with pins 36, 37 of the Body Computer control unit.

See E1050 CAN CONNECTION LINES

The Body Computer also transmits, via pins 6 and 5, signals related to the operating status of the transmission to the display on instrument panel E050, via the B-CAN network.

P/N (Parking/Neutral) position sensor on the automatic transmission solenoid unit L050 is connected via pin 1 to pin B4 of steering lock control unit M089. Its function is to inhibit vehicle start-up.

The pins of connector B of automatic transmission control unit M055 are directly connected to the pins of the automatic transmission solenoid unit L050.

More specifically:

- pins 6, 16, 7, 17 are connected to pins 23, 24, 25, 26 of the automatic transmission solenoid unit L050 and receive the speed selector configuration;

- pins 32 and 22 are connected via pins 17 and 18 of automatic transmission solenoid unit L050 to vehicle speed sensor;3

- pins 33 and 23 are connected via pins 19 and 20 of automatic transmission solenoid unit L050 to Revolution sensor C1;

- pins 25 and 12 are connected via pins 11 and 12 of automatic transmission solenoid unit L050 to the linear lock-up solenoid;

- pins 35 and 15 are connected via pins 7 and 8 of automatic transmission solenoid unit L050 to the linear throttle solenoid;

- pins 26 and 36 are connected via pins 13 and 14 of automatic transmission solenoid unit L050 to the clutch control pressure linear solenoid solenoid;

- pins 31 and 21 are connected via pins 16 and 15 of automatic transmission solenoid unit L050 to the fluid temperature sensor;

- pins 34, 24, 8, 14, 13 are connected via pins 2, 3, 4, 5, 6 of automatic transmission solenoid unit L050 to the 1st, 2nd, 3rd, 4th and 5th speed selection solenoids respectively.

A reverse engagement solenodi is present at pins 10 and 30 of automatic transmission solenoid unit L050.

See E2022 REVERSING LIGHTS

Self-diagnosis of control unit M055 may be performed by connecting to connector C – pin 7 - of Body Computer M001: it receives signals from pin 16 of connector A of control unit M055 via the special diagnostic line (K LINE).

See E8010 DIAGNOSTIC MULTIPLE CONNECTOR