ROBOTIZED GEARBOX - FUNCTIONAL DESCRIPTION

2.0 JTS · Smart gearbox

Operational description

The SELESPEED control unit M54

controls and regulatesthe entire gearbox management system

The direct power supply for the control unit arrives from the batatery, via the line for the CPL maxifuse located on the battery (connector B99 B

) and is protected by fuse F32 of the junction unit under the dashboard B2

, at pin 27 of connector A of M54

The ignition-operated supply (15/54) reaches pin 28 of connector A of M54

See E5010 STARTING AND RECHARING

Pins 1 and 2 of connector A of M54

are earthed.

A group of sensors and potentiometerson the gearbox inform the control unit which gear is engaged, the potentiometers are supplied from pin 73 of connector B; pin 66 provides the reference earth for the gear selector potentiometer K68

returns a signal to pin 51 of connector A; the gear engagement potentiometer K69

returns a signal to pin 39 of connector A; the oil pressure sensor for the hydraulic unit K96

returns a signal to pin 40 of connector A.

The clutch position potentiometer K95

is supplied by pin 79 of connector B, receives a reference earth from pin 59, returns a signal to pin 52 of connector A of M54

Pins 38 and 50 of connector A M54

are connected to the vehicle speed sensor (gearbox output) K77

The gear control assembly H37

is connected to control unit M54

to signal the gear engagement request: these signals are sent from connector A of H37

to pins 67, 74, 68 of connector B of M54

; and to pin 26 of connector A; the reference earth is received from pin 66 of connector B.

Connector B of H37

supplies the LED that lights up the actual panel, switched on by the line (INT) protected by fuse F51 of the junction unit under the dashboard B2

The button for selecting the CITY operating mode H39

is located to the left of the gear selector lever and

is connected to control unit M54

at pin 77 of connector B: the control is lit up by the line (INT) protected by fuse F51 of the junction unit under the dashboard B2

The button for selecting the SPORT logic H32 is located to the right of the gear selector lever and is connected to the control unit M54 at pin 71 of connector B: the control is lit up by the line (INT) protected by fuse F51 of the junction unit under the dashboard B2.

The controls on the steering wheel connected via the clock spring D47

, send signals to pin 75 of connector B of M54

; the reference earth is received from pin 66 of connector B.

Pin 69 of connector B of M54

receives the signal coming from the brake lights switch I30

, with an ignition-controlled power supply (INT) from fuse F37 of the junction unit under the dashboard B2

On the basis of the operating logic the control unit controls the electro-hydraulic unit located in the gearbox which produces the gear changes: pin 31 of connector A controls the electric pump N47

which pressurizes the fluid in the hydraulic unit.

The pump N47

is controlled by a special relay J87

(supplied by the line for fuse F3 of the engine compartment junction unit B1

The control unit then controls the opening of the hydraulic unit solenoid valves:

• the two gear engagement solenoid valves L51 and L52 are controlled from pins 32 and 44 of connector A of M54;
• the two gear engagement solenoid valves L53 and L54 are controlled by pins 29 and 3 of connector A of M54;
• the clutch control solenoid valve L56 is controlled by pin 43 3 of connector A of M54.

From pin 42 of connector A of M54

a safety signal departs for the starting enablement relay J5

which gives the go ahead for starting: pin 50 of the starter motor A20

; the starting request signal arrives at pin 76 of connector B

See E5010 STARTING AND RECHARING

The control unit M54

also manages the doors open signal: the driver''s front door open signal - lock N50

- reaches pin 78 of connector B of M54

The command for the buzzer E47 leaves from pin 80 of connector B

The autodiagnostic data can be read by connecting to connector G of the Body Computer M1

pin 7: it receives the signals from pin 49 of connector A of M54

. (the line is shared with the engine management control unit M10

via the special diagnostic line.

Pins 33 and 45 of connector A of M54 via the CAN

send signals for the "gearbox failure" warning light located in the instrument panel E50

, and for the gear indicator display for the actual instrument.

The speedometer signal is acquired via the CAN.

Pin 48 of connector A is connected to the engine management control unit M10

from which the engine rpm signal is received.