Transfer Case (ETX13C): Overview Infiniti FX50 II

DESCRIPTION

1. Electronic control allows optimal distribution of torque to front/rear wheels to match road conditions.
2. Makes possible stable driving, with no wheel spin, on snowy roads or other slippery surfaces.
3. On roads which do not require AWD, it contributes to improved fuel economy by driving in conditions close to rear-wheel drive.
4. Sensor inputs determine the vehicle's turning condition, and in response tight cornering/braking are controlled by distributing optimum torque to front wheels.
5. It transmits/receives each signal from the following control unit via CAN communication line.

COMPONENT PARTS FUNCTION TABLE

Note. When driving, if there is a large difference between front and rear wheel speed which continues for a long time, fluid temperature of drive system parts becomes too high and AWD warning lamp blinks quickly. (When AWD warning lamp blinks, vehicle changes to rear-wheel drive conditions.) Also, optional distribution of torque sometimes becomes rigid before lamp blinks quickly, but it is not a malfunction. If AWD warning lamp is blinking quickly, stop vehicle and allow it to idle for some time. Blinking will stop and AWD system will be restored. When driving, AWD warning lamp may blink slowly if there is a significant difference in diameter of the tires. At this time, vehicle performance is not fully available and cautious driving is required. (Continues until the engine is turned OFF.) If the warning lamp blinks slowly during driving but remains OFF after the engine is restarted, the system is normal. If it again blinks slowly after driving for some time, vehicle must be inspected. When there is a difference of revolution speed between the front and rear wheel the shift occasionally changes to direct 4-wheel driving conditions automatically. This is not a malfunction.

Scheme 1

1. AWD control unit supplies command current to electric controlled coupling (AWD solenoid).
2. Control clutch is engaged by electromagnet and torque is detected in control clutch.
3. The cam operates in response to control clutch torque and applies pressure to main clutch.
4. Main clutch transmits torque to front wheels according to pressing power.

1. Transmission torque to front wheels is determined according to command current.

Scheme 2

Scheme 3

Component Description

COMPONENT DESCRIPTION TABLE

ECU IDENTIFICATION

AWD control unit part number can be read.

Use this mode to determine and identify the details of a malfunction based on self-diagnostic results or data monitor. AWD control unit gives drive signal to actuator with receiving command from CONSULT-III to check operation of actuator.

1. Controls driving force distribution by signals from each sensor from rear wheel driving mode (0:100) to 4-wheel driving mode (50:50).
2. Rear wheel driving conditions is available by fail-safe function if malfunction is detected in AWD system.

Transmits the following signals via CAN communication to AWD control unit.

1. Vehicle speed signal
2. Stop lamp switch signal (brake signal)

Controls electric controlled coupling by command current from AWD control unit.

AWD solenoid is supplied with voltage by the internal circuit of AWD control unit.

Transmits the following signals via CAN communication to AWD control unit.

1. Accelerator pedal position signal
2. Engine speed signal

1. Controls driving force distribution by signals from each sensor from rear wheel driving mode (0:100) to 4-wheel driving mode (50:50).
2. Rear wheel driving conditions is available by fail-safe function if malfunction is detected in AWD system.

1. Controls driving force distribution by signals from each sensor from rear wheel driving mode (0:100) to 4-wheel driving mode (50:50).
2. Rear wheel driving conditions is available by fail-safe function if malfunction is detected in AWD system.

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

Supplies power to AWD control unit.

1. Turns ON when there is a malfunction in AWD system. AWD warning lamp indicates the vehicle is in fail-safe mode and shifting to rear-wheel drive or 4-wheel drive (front-wheels still have some driving torque).
2. Also turns ON when ignition switch is turned ON, for the purpose of lamp check. Turns OFF approximately for 1 second after the engine starts if system is normal.

AWD warning lamp does not turn ON when the ignition switch is turned to ON.

AWD warning lamp does not turn OFF several seconds after the engine started.

Heavy tight-corner braking symptom occurs when the vehicle is driven and the steering wheel is turned fully to either side after the engine is started.

Note. Light tight-corner braking symptom may occur depending on driving conditions. This is not malfunction.

Vehicle does not enter 4-wheel drive mode even though AWD warning lamp turned to OFF.

While driving, AWD warning lamp blinks 2 times in 1 second and it turns OFF after 1 minute.

1. This symptom protects drivetrain parts when a heavy load is applied to the electric controlled coupling and multiple disc clutch temperature increases. Also, optional distribution of torque sometimes becomes rigid before lamp blinks quickly. Both cases are not malfunction.
2. When this symptom occurs, stop vehicle and allow it to idle for some times. Blinking will stop and system will be restored.

AWD warning lamp blinks at approximately 2 seconds intervals while driving.

OPERATION PROCEDURE

1. Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock will remain released with both battery cables disconnected and the steering wheel can be turned.
4. Perform the necessary repair operation.
5. When the repair work is completed, re-connect both battery cables. With the brake pedal released, turn the push-button ignition switch from ACC position to ON position, then to LOCK position. (The steering wheel will lock when the push-button ignition switch is turned to LOCK position.)
6. Perform self-diagnosis check of all control units using CONSULT-III.