SsangYong Musso. Manual - part 462

AUTOMATIC TRANSMISSION 5A-25

producing a low resistance.

Temperature/Resistance characteristics and location within the solenoid wiring loom are given in tables 3-1 and 3-
2, and figures 3.2 and 3.3.

If the transmission sump temperature exceeds 135°C, the TCU will impose converter lock-up at lower vehicle
speeds and in some vehicles flashes the mode indicator lamp. This results in maximum oil flow through the
external oil cooler and eliminates slippage in the torque converter. Both these actions combine to reduce the oil
temperature in the transmission.

Connects To

Solenoid 1

Solenoid 2

Solenoid 3

Solenoid 4

Solenoid 5

Solenoid 6

Solenoid 7

Solenoid 5

Temp Sensor

Wire Color

Red

Blue

Yellow

Orange

Green

Violet

Brown

Green

White

Pin No.

Table 3.2 - Pin No. Codes for Temperature Sensor Location In Solenoid Loom

Figure 3.3 - Temperature Sensor Location in Solenoid Loom

5A-26 AUTOMATIC TRANSMISSION

I n h i b i t o r

Switch

Throttle Position Sensor

The throttle position sensor(TPS) is a resistance potentiometer
mounted on the throttle body of the engine.

It transmits a signal to the TCU proportional to the throttle plate
opening.

The potentiometer is connected to the TCU by three wires:

5 volts positive supply, earth and variable wiper voltage.

Throttle voltage adjustments are as follows:

Closed throttle voltage is 0.2V to 1.0V.

Wide open throttle voltage is 3V -4.7V.

These measurements are taken between pins 29 and 27 of
the TCU.

Maintaining good shift feel through the transmission life span
is dependant on having an accurate measure of

the engine throttle position. To achieve this the TCU
continuously monitors the maximum and minimum throttle

potentiometer voltages and, if a change occurs, stores the new
voltage values.

However these limits will be lost and will require relearning
should a new TCU be installed, or the throttle calibration data
is cleared by the execution of a particular sequence, This last
instance depends on the installation, and reference should be
made to the Diagnostics Section of this manual. The relearning
will happen automatically

Notice

Above figure of T.P.S. is for the diesel engine

which is installed on the injection pump.

Gear Position Sensor

The gear position sensor is incorporated in the inhibitor switch
mounted on the side of the transmission case.

(Refer to figure 3.5.) The gear position sensor is a multi-function
switch providing three functions:

Inhibit starting of the vehicle when the shift lever is in a
position other than Park or Neutral

Illuminate the reversing lamps when Reverse is
selected indicate to the TCU which lever position has
been selected by way of a varying resistance (Refer to
table 3.3.)

Figure 3.5 - Inhibitor Switch

AUTOMATIC TRANSMISSION 5A-27

Shift Lever Position

Manual 1

Manual 2

Manual 3

Drive

Netural

Reverse

Park

Resistance (OHMS)

1k - 1.4k

1.8k - 2.2k

3k - 3.4k

4.5k - 4.9k

6.8k - 7.2k

10.8k - 11.2k

18.6k - 19k

Table 3.3 - Readings for Resistance/Shift Lever Positions

Diagnostics Inputs

The diagnostics control input or K-line is used to initiate the outputting of diagnostics data from the TCU to a diagnostic
test instrument. This input may also be used to clear the stored fault history data from the TCU’s

retentive memory. Connection to the diagnostics input of the TCU is via a connector included in the vehicle’s wiring

harness or computer interface. Refer to the vehicle manufacturer’s manual for the location of the self test

connectors.

Battery Voltage Monitoring Input

The battery voltage monitoring input connects to the positive side of the battery. The signal is taken from the

main supply to the TCU.

If operating conditions are such that the battery voltage at the TCU falls below 11.3V the transmission will adopt a ‘low
voltage’ mode of operating in which shifts into first gear are inhibited. All other shifts are allowed but may not occur
because of the reduced voltage. This condition normally occurs only when the battery is in poor condition.

When system voltage recovers, the TCU will resume normal operation after a 3 second delay period.

TCU Outputs

The outputs from the TCU are supplied to the components described below:

Solenoids

The TCU controls seven solenoids. Solenoids 1 to 6 (S1 to S6) are mounted in the valve body, while Solenoid 7 (S7)
is mounted in the pump cover. The normal state (OPEN/CLOSED) and the functions associated with the solenoids
are detailed in table 3.4. Table 3.5 details the S1 and S2 logic for static gear states. The logic during gear changes for
S1 to S4 and S7 is detailed in table 3.6.

5A-28 AUTOMATIC TRANSMISSION

Table 3.4 - Solenoid States and Functions

Table 3.5 - Solenoid Logic for Static Gear States

Solenoids 1 and 2

Solenoids 3 and 4

Solenoid 5

Solenoid 6

Solenoid 7

S1 and S2 are normally open On/off solenoids that set the selected gear.

These solenoids determine static gear position by operating the shift valves.

Refer to table 3.5. Note that S1 and S2 solenoids also send signal pres-

sure to allow or prohibit rear band engagement.

S3 and S4 are normally open On/off solenoids that combine to control

shift quality and sequencing. S3 switches the clutch regulator valve off or

on. S4 switches the front band regulator valve off or on.

S5 is a variable force solenoid that ramps the pressure during gear

changes. This solenoid provides the signal pressure to the clutch and

band regulator, thereby controlling the shift pressures.

S6 is a normally open On/off solenoid that sets the high/low level of line

pressure, Solenoid off gives high pressure.

S7 is a normally open On/off solenoid that controls the application of the

converter clutch. Solenoid on activates the clutch.

OFF

Gear

1st

2nd

3rd

4th

Reverse

Neutral

Park

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