P1813

P1813 4WD Shift Switch

Description

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.

DTC Logic

DTC Detection Logic






DTC Confirmation Procedure

1. DTC CONFIRMATION PROCEDURE

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

Is DTC P1813 displayed?
YES
Perform diagnosis procedure. Refer to "Diagnosis Procedure".
NO
Inspection End.

Diagnosis Procedure

Regarding Wiring Diagram information, refer to [Transfer Control Unit: Wiring Diagram] [1][2]Electrical Diagrams.

1. CHECK 4WD SHIFT SWITCH SIGNAL

With SDT

1 Turn ignition switch "ON".
2 Select "Data list" mode for "4WD" with SDT.
3 Read out ON/OFF switching action of the "2WD SWITCH", "4H SWITCH", "4L SWITCH" with operating 4WD shift switch.
Without SDT

1 Turn ignition switch "ON".
2 Check voltage between transfer control unit harness connector terminals and ground.











Are the inspection results normal?
YES
GO TO 5.
NO
GO TO 2.

2. CHECK 4WD SHIFT SWITCH POWER SUPPLY CIRCUIT

1 Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2 Disconnect 4WD shift switch harness connector.
3 Check voltage between 4WD shift switch harness connector terminal 1 and ground.











4 Turn ignition switch "ON". (Do not start engine.)





5 Check voltage between 4WD shift switch harness connector terminal 1 and ground.






Is there voltage?
YES
GO TO 3.
NO
1 Check harness for short or open between 4WD shift switch harness connector terminal 1 and transfer shut off relay 2 harness connector E157 terminal 5 and 10 A fuse (No. 58 located in the fuse and relay box). If any items are damaged, repair or replace damaged parts.
2 Perform trouble diagnosis for power supply circuit. Refer to [P1801, P1811 Power Supply Circuit for Transfer Control Unit] P1801.

3. CHECK HARNESS BETWEEN 4WD SHIFT SWITCH AND TRANSFER CONTROL UNIT

1 Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2 Disconnect transfer control unit harness connector and the 4WD shift switch harness connector.
3 Check continuity between the following terminals.





- Transfer control unit harness connector M152 terminal 14 and 4WD shift switch harness connector M141 terminal 3.
- Transfer control unit harness connector M152 terminal 15 and 4WD shift switch harness connector M141 terminal 5.
- Transfer control unit harness connector M152 terminal 16 and 4WD shift switch harness connector M141 terminal 6.






Also check harness for short to ground and short to power.

Is there continuity?
YES
GO TO 4.
NO
Repair or replace damaged parts.

4. CHECK 4WD SHIFT SWITCH

1 Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2 Remove 4WD shift switch harness connector.
3 Operate 4WD shift switch and check continuity between 4WD shift switch terminals.











Are the inspection results normal?
YES
GO TO 5.
NO
Replace 4WD shift switch.

5. CHECK TRANSFER CONTROL UNIT

Check transfer control unit input/output signal. Refer to [Transfer Control Unit: Reference Value] Pinout Values and Diagnostic Parameters.

Are the inspection results normal?
YES
GO TO 6.
NO
Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.

6. CHECK DTC

Drive the vehicle and then perform "DTC check".

Is DTC P1813 displayed?
YES
Replace transfer control unit. Refer to [Transfer Control Unit: Removal and Installation] Service and Repair.
NO
Inspection End.

Component Inspection

1) Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2) Remove 4WD shift switch harness connector.
3) Operate 4WD shift switch and check continuity between 4WD shift switch terminals.











4) If the inspection results are abnormal replace the 4WD shift switch.