Rear Differential Description
The differential assembly uses a hypoid bevel pinion and gear.
The differential assembly is decisive in that the drive power is concentrated there. Therefore, use of genuine parts and specified torque is compulsory. Further, because of sliding tooth meshing with high pressure between hypoid bevel pinion and gear, it is mandatory to lubricate them by hypoid gear oil.
Scheme 1
Coupling Description
Coupling is installed in the forward of rear differential. The road situation and driving are judged with 4WD control module based on information from sensor and each control module, and the distribution of driving force of the front and rear wheel has been changed by controlling the current to coupling. Coupling air temperature sensor is installed in coupling case and measures the temperature in coupling.
4WD system has three driving positions (2WD, 4WD-auto, 4WD-lock). The position corresponding to the running situation can be selected by 2WD/4WD switch.
Indicator Operation
The 4WD control module output operation signal of the 4WD AUTO indicator and the 4WD LOCK indicator. Indicators as follows in order to inform what state the 4WD control system is.
| Operation | Condition | |
|---|---|---|
| Indicator | ||
| 4WD AUTO indicator | OFF | Ignition switch is OFF. Vehicle is at "2WD" position or "4WD-lock" position. |
| ON | Within 2 seconds after ignition switch is turn ON (checking indicator operation). Vehicle is at "4WD-auto" position. 4WD control module detects DTC of 4WD control system. | |
| Blinking at intervals of 2 seconds continuously | 4WD control module detects the rotation difference of front wheel and rear wheel and/or temperature of rear differential more than specified temperature. | |
| 4WD LOCK indicator | OFF | Ignition switch is OFF. Vehicle is at "2WD" position or "4WD-auto" position. |
| ON | Within 2 seconds after ignition switch is turn ON (checking indicator operation). Vehicle is at "4WD-lock" position. 4WD control module detects DTC of 4WD control system. | |
4WD CONTROL SYSTEM DESCRIPTION
Description of 4WD Control System Component Function
| Part Name | Function |
|---|---|
| 2WD/4WD switch | Output ON and OFF signal of 2WD/4WD switch to 4WD control module. |
| 4WD AUTO indicator | Indicates vehicle is at 4WD-auto position or not. |
| 4WD LOCK indicator | Indicates vehicle is at 4WD-lock position or not. |
| 4WD control module | Controlled of current to coupling assembly and vehicle switching to each position. Diagnosis 4WD control system components. Output operation signal of indicator to BCM. |
| Coupling assembly | The driving force of corresponding to the signal from 4WD control module transmitted to the rear wheel. |
DESCRIPTION OF 4WD CONTROL SYSTEM COMPONENT FUNCTION
CAN Communication System Description
Refer to CAN COMMUNICATION SYSTEM DESCRIPTION .
Scheme 2
Scheme 3
| Terminal | Circuit | Terminal | Circuit |
|---|---|---|---|
| G26-2 | Coupling assembly (ground) | G26-14 | "4WD lock" switch |
| G26-3 | Coupling assembly (power) | G26-21 | Data link connector (DLC) |
| G26-10 | Ground | G26-22 | CAN communication line (high) |
| G26-11 | Power source for internal memory | G26-23 | CAN communication line (low) |
| G26-12 | Power source | G26-24 | Coupling air temperature sensor (ground) |
| G26-13 | "4WD" switch | G26-25 | Coupling air temperature sensor (power) |
TERMINAL ARRANGEMENT OF 4WD CONTROL MODULE
Scheme 4
4WD Position Indicator Operation Check
- Turn ignition switch to OFF position.
- Check that 4WD position indicators turn on for about 2 seconds and then turns off. If any faulty condition is found, proceed to «4WD POSITION INDICATOR DOES NOT COME ON AT IGNITION SWITCH ON BUT ENGINE STOPS»(ref-514592-S07926344142012112100000) or «4WD POSITION INDICATOR REMAINS ON STEADY AT IGNITION SWITCH ON»(ref-514592-S26584367662012112100000) .
4WD Control System Operation Inspection
Note. When the vehicle speed exceeds the specified level while running in "4WD-lock" mode, the mode changes to "4WD-auto" mode automatically. If ABS operates while "4WD-control" mode is being changed, such change of "4WD-control" mode is discontinued.
- Inspect switch operation from "4WD-auto" to "2WD" as follows. Start engine. Push 2WD/4WD switch to "2WD" position. Check that 4WD AUTO indicator and 4WD LOCK indicator not come ON.
- Inspect switch operation from "2WD" to "4WD-auto" as follows. Start engine. Push 2WD/4WD switch to "AUTO" position. Check that 4WD AUTO indicator comes ON steady and 4WD LOCK indicator not come ON.
- Inspect switch operation from "4WD-auto" to "4WD-lock" as follows. Start engine. Push 2WD/4WD switch to "LOCK" position, and keep it for 3 seconds or more. Check that 4WD AUTO indicator not come ON and 4WD LOCK indicator comes ON steady.
- Inspect switch operation from "4WD-lock" to "4WD-auto" as follows. Start engine. Push 2WD/4WD switch to "AUTO" position. Check that 4WD AUTO indicator comes ON steady and 4WD LOCK indicator not come ON.