Contents Section: Transfer Case All sections

Transfer Case (TX15B): Overview Nissan Pathfinder III рестайлинг

Transfer Case 1 illustration ~935 words

Scheme 341

Scheme 341: WORK FLOW

COMPONENT DESCRIPTION

ComponentsFunction
Transfer control unitControls transfer control device and controls shifts between 2WD/4WD and 4H/4LO.
Transfer control deviceIntegrates actuator motor and actuator position switch.
Actuator motorMoves shift rods when signaled by transfer control unit.
Actuator position switchDetects actuator motor position.
Wait detection switchDetects if transfer case is in 4WD.
4LO switchDetects if transfer case is in 4LO.
ATP switchDetects if transfer case is in neutral.
4WD shift switchAllows driver to select from 2WD/4WD and 4H/4LO.
4WD warning lampIlluminates if malfunction is detected in 4WD system. Flashes (1 flash / 2 seconds) if rotation difference of front wheels and rear wheels is large.
ATP warning lampIndicates that A/T parking mechanism does not operate when A/T selector lever is in "P" position because transfer case is in neutral.
4WD shift indicator lampDisplays driving range selected by 4WD shift switch.
4LO indicator lampDisplays 4LO range.
ABS actuator and electric unit (control unit)Transmits the following signals via CAN communication to transfer control unit. Vehicle speed signal Stop lamp switch signal (brake signal)
TCMTransmits the following signal via CAN communication to transfer control unit. Output shaft revolution signal A/T position indicator signal (transmission range switch signal)
ECMTransmits engine speed signal via CAN communication to transfer control unit.

Description

The transfer control unit controls the transfer control device which controls shifts between 4H and 4LO and between 2WD and 4WD. When the vehicle battery is removed, the power supply to the transfer control unit is interrupted, and self-diagnosis memory function is suspended. These DTCs may also set when the power supply voltage for the transfer control unit is abnormally low while driving.

The transfer control unit controls the transfer control device which controls shifts between 4H and 4LO and between 2WD and 4WD. A DTC may set when any of the following occur

  1. Malfunction is detected in the memory (RAM) system of transfer control unit.
  2. Malfunction is detected in the memory (ROM) system of transfer control unit.
  3. Malfunction is detected in the memory (EEPROM) system of transfer control unit.
  4. AD converter system of transfer control unit is malfunctioning.

The transmission control module (TCM) transmits the output shaft revolution signal via CAN communication to Transfer control unit. DTC P1807 will set when a malfunction is detected in the output shaft revolution signal or an improper signal is input while driving.

The ABS actuator and electric unit (control unit) transmits a vehicle speed signal via CAN communication to the transfer control unit. DTC P1808 sets when a malfunction is detected in the vehicle speed signal that is output from the ABS actuator and electric unit (control unit) or an improper signal is input while driving.

The 4LO switch detects that the transfer case is in 4LO range. DTC P1810 will set when an improper signal from the 4LO switch is input due to an open or short circuit.

The 4WD shift switch allows the driver to select 2WD or 4WD and 4H or 4LO. DTC P1813 will set if more than two switch inputs are simultaneously detected by the transfer control unit due to a short circuit in the 4WD shift switch.

The wait detection switch detects if the transfer case is in 4WD. DTC P1814 will set if an improper signal from the wait detection switch is input due to open or short circuit.

The transmission range switch transmits the A/T position indicator signal (transmission range switch signal) via CAN communication to the transfer control unit. DTC P1816 will set when the transmission range switch signal is malfunctioning or there is a communication error.

The actuator motor receives signals from the transfer control unit and controls shift rods which shift the transfer case. DTC P1817 will set when any of the following occur

  1. Motor does not operate properly due to open or short circuit in actuator motor.
  2. Malfunction is detected in the actuator motor. (When 4WD shift switch is operated and actuator motor does not operate)
  3. Malfunction is detected in transfer shift high relay or transfer shift low relay.

The actuator position switch detects the current actuator motor range. DTC P1818 will set if either of the following occur

  1. Improper signal from actuator position switch is input due to open or short circuit.
  2. Malfunction is detected in actuator position switch.

The transfer control device integrates the actuator motor and actuator position switch. DTC P1819 will set if either of the following conditions exist

  1. Malfunction occurs in transfer control device drive circuit.
  2. Malfunction is detected in transfer shut off relay 1 and transfer shut off relay 2.

The ECM transmits the engine speed signal via CAN communication to the transfer control unit. DTC P1820 will set when either of the following occur

  1. Malfunction is detected in engine speed signal that is output from the ECM.
  2. Improper signal is input while driving.

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 communicate data but selectively reads required data only.

4WD warning lamp does not turn ON when turning ignition switch to ON.

4WD shift indicator lamp and 4LO indicator lamp do not turn ON for approx. 1 second when turning ignition switch to ON.

4WD shift indicator lamp or 4LO indicator lamp do not change when switching the 4WD shift switch.

ATP warning lamp does not turn ON when the transfer case is switched in or out of 4LO with the A/T selector lever in N position.

The 4WD shift indicator lamp keeps flashing.

The 4WD warning lamp flashes slowly while driving (1 time / 2 seconds). The lamp continues to flash until the ignition switch is turned OFF.

The ATP indicator does not come on when the transfer is in neutral and the A/T lever is in neutral or, the ATP indicator stays on when the transfer case is not in neutral.

OPERATION PROCEDURE

  1. Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
  2. Use the Intelligent Key or mechanical key to turn the ignition switch to the "ACC" position. At this time, the steering lock will be released.
  3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
  4. Perform the necessary repair operation.
  5. When the repair work is completed, return the ignition switch to the "LOCK" position before connecting the battery cables. (At this time, the steering lock mechanism will engage.)
  6. Perform a self-diagnosis check of all control units using CONSULT.