P1804

P1802 - P1804, P1809 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. A DTC may set when any of the following occur:

- Malfunction is detected in the memory (RAM) system of transfer control unit.

- Malfunction is detected in the memory (ROM) system of transfer control unit.

- Malfunction is detected in the memory (EEPROM) system of transfer control unit.

- AD converter system of transfer control unit is malfunctioning.

DTC Logic

DTC Detection Logic






DTC Confirmation Procedure

1. DTC CONFIRMATION PROCEDURE

1 Turn ignition switch ON.
2 Perform "DTC check".

Are DTCs "P1802 - P1804 or P1809 detected?
YES
Perform diagnosis procedure. Refer to "Diagnosis Procedure".
NO
Inspection End.

Diagnosis Procedure

1. INSPECTION START

Do you have SDT?

YES or NO
YES
GO TO 2.
NO
GO TO 3.

2. PERFORM DTC CHECK (WITH SDT)

1 Turn ignition switch "ON".
2 Select "DTC check" mode for "4WD" with SDT.
3 Touch "Clear".
4 Turn ignition switch "OFF" and wait at least 10 seconds.
5 Perform the "DTC check" again.

Is the "CONTROL UNIT 1 [P1802]", "CONTROL UNIT 2 [P1803]", "CONTROL UNIT 3 [P1804]" or CONTROL UNIT 4 [P1809]" displayed?
YES
Replace transfer control unit. Refer to [Transfer Control Unit: Removal and Installation] Service and Repair.
NO
Inspection End.

3. PERFORM SELF-DIAGNOSIS (WITHOUT SDT)

1 Perform the self-diagnosis and then erase self-diagnostic results. Refer to [SDT Function (4WD)] Scan Tool Testing and Procedures.
2 Perform the self-diagnosis again.

Do the self-diagnostic results indicate AD converter?
YES
Replace transfer control unit. Refer to [Transfer Control Unit: Removal and Installation] Service and Repair.
NO
Inspection End.