Transfer Case -GF1A: Other Toyota RAV4 III

PRECAUTION

1. Before disassembling the transfer assembly, thoroughly clean it by removing any foreign matter. This will help prevent contamination during disassembly and reassembly.
2. When removing the transfer cover or any other light alloy parts, do not pry them off with a screwdriver or other tool that may cause damage. Instead, tap the parts with a plastic-faced hammer.
3. Always arrange removed parts in the order they were removed and protect them from foreign matter.
4. Before installation of each part, thoroughly clean and dry it. Then apply hypoid gear oil to it. Do not use alkaline chemicals to clean aluminum parts, rubber parts or ring gear set bolts. Also, do not use white gasoline or other cleaning oils to clean O-rings, oil seals or rubber parts.
5. Coat any sliding surface or rotating parts with hypoid gear oil.
6. Do not directly fix a part in a vise. Place aluminum plates between the part and vise.
7. Replace any damaged or deformed snap rings with new ones.
8. Do not allow the case's mating surface to be scratched. Scratches may lead to oil leakage.
9. Using a razor blade and gasket scraper, remove old Toyota Genuine Seal Packing Black, Three Bond 1207B or Equivalent from the seal surface.
10. Clean all parts to remove excess Toyota Genuine Seal Packing Black, Three Bond 1207B or Equivalent completely.
11. Clean the sealing surface with solvent so that no residue remains on the seal surface.
12. Apply Toyota Genuine Seal Packing Black, Three Bond 1207B or Equivalent in a continuous line of approximately 1.2 mm (0.047 in.) in diameter along the sealing surface.
13. Be sure to assemble parts within 10 minutes of Toyota Genuine Seal Packing Black, Three Bond 1207B or Equivalent application. Otherwise, the Toyota Genuine Seal Packing Black, Three Bond 1207B or Equivalent must be removed and reapplied.
14. After sealing parts, do not allow oil to contact the seal for at least 1 hour.
15. Do not allow scratches on a part's contact surface with an oil seal or gasket. Scratches may lead to oil leakage.
16. When press-fitting an oil seal, be careful not to damage the lip of the oil seal and its periphery.

1. TROUBLESHOOTING PRECAUTION NOTE: Since the Active torque control system (4WD control system) may be influenced by a malfunction in other systems, be sure to check for DTCs in the other systems. When removing and installing the 4WD control ECU and each sensor, be sure to check that the normal display is output in test mode inspection and in DTC output inspection after installing all the parts. If the DTC of the CAN communication line is output, repair the malfunction in the communication line and troubleshoot the 4WD control system. Since the CAN communication line has its own length and route, it cannot be repaired temporarily with a bypass wire, etc.

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1. GENERAL DESCRIPTION The active torque control 4WD system detects the driving conditions based on signals from each ECU, each switch, the steering angle sensor, the wheel speed sensor, and the yaw rate sensor. The system controls the electronic current passing through the linear solenoid of the electromagnetic coupling, and performs electronic control to distribute the optimum torque to the rear wheels. Main components and their functions. COMPONENTS AND FUNCTIONS Component Function 4WD Indicator Light Displays warning to driver when system malfunctions Stop Light Switch Detects brake operation Throttle Position Sensor Detects opening angle of throttle Park/Neutral Position Switch Detects "P" position Steering Angle Sensor Detects turning of steering wheel 4WD Linear Solenoid Detects electronic control limiting clutch operation using signals from 4WD control ECU Skid Control ECU with Actuator Detects signals from each sensor and outputs them to 4WD control ECU 4WD Control ECU Detects signals from each sensor via skid control ECU to operate linear solenoid and control system Crankshaft Position Sensor Detects engine rpm and inputs it into ECM Yaw Rate Sensor Detects forward and rearward acceleration of vehicle, and inputs it into Ambient Temperature Detects external ambient temperature and inputs it into body ECU Electromagnetic Coupling Based on amount of current sent from 4WD control ECU, torque is distributed to rear wheels 4WD Lock Switch Change of side auto mode for lock mode 4WD Lock Mode Indicator Light Lock mode control status is communicated to driver through indicator light illumination When lock mode is turned ON, indicator light blinks twice and then remains illuminated. When lock mode is turned OFF, indicator light turns OFF.
2. DRIVING FUNCTION TF DRIVING FUNCTION TF Vehicle Condition Status Control at Vehicle Startup This controls the amount of side-way sliding that occurs at rear of vehicles when accelerating from stop to improve acceleration and hill climbing capacity Slip Control at Vehicle Startup This helps prevent vehicle from sliding sideways. When accelerating a stopped vehicle with the steering wheel turned, it ensures steering stability Slip Control This ensures high turning performance and that stability is not affected by road surface conditions during mid and high speed running Control During Acceleration This controls straight-line running when accelerating during mid and high speeds to ensure straight-line stability of the vehicle
3. REFERENCE MECHANISM Electromagnetic coupling The outer part of the main clutch is attached together with the front housing. The inner part of the main clutch is attached together with the shaft. The control clutch is attached together with the control cam. The activation energy from the transfer is transferred from the propeller shaft to the front housing. However, when the linear solenoid is not operating, the main clutch and control clutch are in a free state, and the activation energy from the transfer is not transferred to the rear wheels. If current is applied to the linear solenoid, the solenoid magnetizes, and the electromagnet pull force causes the armature to attach to the control clutch side. Or, if there is a difference between the rotation speed of the front and rear wheels and the control clutch attaches, a difference occurs in the rotation of the main cam attached to the shaft and the control cam attached to the front housing. As a result, each ball pushes its cam, and the main clutch attaches. The activation energy from the front housing passes through main clutch to the shaft, and then to the rear differential. Then the activation energy is transferred to the rear wheels. Depending on the rotation difference between the front and rear wheels, the system controls the current flowing to the linear solenoid. Then the activation energy applied to the rear wheels is smoothly controlled. Depending on the amount of current, the restraint energy of the outer and inner side of the main clutch changes, and the activation energy from the propeller shaft is smoothly controlled from a limited condition to condition that is nearly a direct-link 4WD condition.

FAIL-SAFE CHART

1. FAIL-SAFE FUNCTION If following malfunctions occur, the 4WD control ECU will stop the function of 4WD control system or partly change the function to control the system. If a malfunction occurs in the sensor signal or actuator, the flow of electricity to the linear solenoid of the electrical coupling is prohibited. As a result, the system enters front wheel drive condition. When a component of the system malfunctions and the fail-safe function activates, the component operation is prohibited. However, if the system is controlling the component and the fail-safe function activates, the system operation is gradually stopped to prevent sudden changes in the vehicle condition. When system control is not possible, the warning light is illuminated to stop operation of the system operation.