Components and components location
Component Location
1. Relif valve 2. Pressure sensor | 3. Oil hydraulic motor 4. Coupling assembly |
Direct Electro Hydraulic Actuator Coupling. Description and operation
Description
4WD ECU processes signals from various sensors and determines the current road and driving conditions. The ECU then utilizes this information to implement precision control over the 4WD coupling's multi-plate clutch and variably adjust the amount of torque delivered tothe rear wheels.
Four Wheel Drive (4WD) transfer mode selection
1. | AUTO MODE:
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2. | LOCK MODE:
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Electronic Coupling - 4WD Control (By Driving Condition)
1. | Cruising (Auto Mode)
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2. | Cornering (Auto Mode)
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3. | Wheel Slip (Auto Mode)
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Operation
Electronic Coupling
1. | The power is delivered in the following order: Transmission -> Transfer -> Propeller shaft |
2. | AWD ECU calculates the necessary amount of rear-wheel torque and sends the corresponding driving current to the actuator (electronic motor and hydraulic pump). |
3. | The piston operates by the oil pressure and the friction is generated. Then, the clutch is engaged. |
4. | The power is delivered to the differential by the engaged clutch and the driving power is generated in to the rear wheel. |
Direct Electro Hydraulic Actuator Coupling. Repair procedures
Inspection
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• | All units are filled up with coupling fluid (ultra-low viscosity ATF) prior to shipping. Inspection, fill-up, and replacement of coupling fluid is therefore not necessary (zero maintenance, lifetime fluid). |
Removal
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Coupling Maintenance Precautions
Maintain the coupling at a horizontal level.
• | Refer to the handling caution level (A) when servicing the coupling (removal, installation, replacement, etc.). |
• | Always maintain a horizontal posture. |
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• | Be careful not to damage the parts located under the vehicle (floor under cover, fuel filter, fuel tank and canister) when raising the vehicle using the lift. (Refer to General Information - "Lift and Support Points") |
1. | Loosen the rear propeller shaft assembly mounting bolts and then removing the rear propeller shaft assembly (A). Tightening torque : 49.0 - 68.6N.m (5.0 - 7.0kgf.m, 36.2 - 50.6lb-ft) |
2. | Using a flat tool, separate the propellar shaft from 4WD coupling assembly. |
3. | Disconnect the oil hydrulic motor connector (A). |
4. | Disconnect the pressure sensor connector (A). |
5. | Loosen the bolts and then removing the coupling assembly (A). Tightening torque : 58.9 - 64.7 N.m (5.8 - 6.6kgf.m, 41.9 - 47.7 lb-ft) |
Installation
1. | To install, reverse the removal procedures.
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2. | After replacing the coupling, reset the 4WD ECU's clutch learing using the diagnostic tool. (Refer to 4WD Control System - "Repair procedures") |
Oil hydraulic Motor(Actuator). Description and operation
Description
The 4WD ECM controls the Pump Motor Pump (Actuator) to generating an oil pressure. The pressure engages a multiple disk clutch to transfer torque to the rear wheels. The torque to the rear wheels varies according to the pressure on the clutch.
Oil hydraulic Motor(Actuator). Schematic diagrams
Circuit Diagram
Oil hydraulic Motor(Actuator). Repair procedures
Inspection
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• | If you have trouble code related to the oil hydraulic motor (actuator), check oil hydraulic motor (actuator) according to the inspection process. |
Oil Hydraulic Motor (Actuator) Inspection Procedure
Removal
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• | Be careful not to damage the parts located under the vehicle (floor under cover, fuel filter, fuel tank and canister) when raising the vehicle using the lift. (Refer to General Information - "Lift and Support Points") |
1. | Remove the coupling assembly. (Refer to 4 Wheel Drive (4WD) System - "Coupling Assembly") |
2. | Keep going perpendicular state after remove the coupling assembly.
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3. | Remove the hydraulic motor (A) after loosening bolts with hex wrench.
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Installation
1. | Before installation, wipe the surface with a clean cloth. |
2. | Check the O-rings (A) of the new hydraulic motor (actuators).
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3. | Tighten the bolts after install the hydraulic motor.
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4. | Wipe the flowed oil to around the surface with a clean cloth. |
5. | Install the coupling assembly. (Refer to 4 Wheel Drive (4WD) System - "Coupling Assembly") |
Pressure Sensor. Description and operation
Description
The 4WD ECU makes a Motor Pump(Actuator) turn round for generating an oil pressure. And then it presses a multiple disk clutch and transfers the generated torque into rear wheels. Its torque value varies according to a pressure status.
• | Component location |
Pressure Sensor. Schematic diagrams
Circuit Diagram
Pressure Sensor. Repair procedures
Inspection
Measure the resistance of pressure sensor
1. | Turn ignition switch OFF. |
2. | Disconnect the pressure sensor connector. |
3. | Measure resistance between sensor terminal and terminal. |
4. | Check the measured resistance. (Refer to table) |
[Table 1]
Terminal | Resistance |
PIN 2 – PIN 3 | 1.59 - 2.39 kΩ |
PIN 1 – PIN 3 | 152 - 231.6 kΩ |
PIN 1 – PIN 2 | 153.52 - 233.88 kΩ |
Removal
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• | Be careful not to damage the parts located under the vehicle (floor under cover, fuel filter, fuel tank and canister) when raising the vehicle using the lift. (Refer to General Information - "Lift and Support Points") |
1. | Remove the coupling assembly. (Refer to 4 Wheel Drive (4WD) System - "Coupling Assembly")
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2. | Remove the pressure sensor (A).
Tightening torque: 10.8 - 14.7 N.m (1.1 - 1.5 kgf.m, 8.0 - 10.8 lb-ft) |
Installation
1. | To install, reverse the removal procedure. |
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• | Check the cleanliness of the pressure sensor before installation. |
• | Check the pressure sensor O-ring (A). |
• | Keep it level with the sticker (A) on the top of the coupling. |
Transfer Assembly
Transfer Fluid. Repair procedures Inspection • Transfer oil should be inspected and refilled every 60,000 km (40,000 mile) / 4 year. • Be careful not to damage the parts located ...
See also:
Front Driveshaft. Repair procedures
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Starting System
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Side Impact Sensor (SIS). Repair procedures
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