P1810

P1810 4 LO Switch

Description

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.

DTC Logic

DTC Detection Logic






DTC Confirmation Procedure

1. DTC CONFIRMATION PROCEDURE

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

Is DTC P1810 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 4LO POSITION SWITCH SIGNAL

With SDT

1 Start engine.
2 Select "Data list" mode for "4WD" with SDT.
3 Read out the value of "4L POSI SW".






Without SDT

1 Start engine.
2 Check voltage between transfer control unit harness connector terminal and ground.











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

2. CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND 4LO SWITCH

1 Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2 Disconnect transfer control unit harness connector and the 4LO switch harness connector.
3 Check continuity between transfer control unit harness connector M152 terminal 24 and 4LO switch harness connector F60 terminal 13.











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

Is there continuity?
YES
GO TO 3.
NO
Repair or replace damaged parts.

3. CHECK GROUND CIRCUIT

1 Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2 Disconnect 4LO switch harness connector.
3 Check continuity between 4LO switch harness connector F60 terminal 12 and ground.











Also check harness for short to power.

Is there continuity?
YES
GO TO 4.
NO
Repair open circuit or short to power in harness or connectors.

4. CHECK 4LO SWITCH

1 Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2 Disconnect 4LO switch harness connector.
3 Remove 4LO switch. Refer to [4WD System: Component Parts Location] Locations.
4 Push and release 4LO switch and check continuity between 4LO switch terminals 12 and 13.











Are the inspection results normal?
YES
GO TO 5.
NO
Replace 4LO 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 P1810 displayed?
YES
Replace transfer control unit. Refer to [4WD System: Component Parts Location] Locations.
NO
Inspection End.

Component Inspection

1) Turn ignition switch "OFF". (Stay for at least 5 seconds.)
2) Disconnect 4LO switch harness connector.
3) Remove 4LO switch. Refer to [4WD System: Component Parts Location] Locations.
4) Push and release 4LO switch and check continuity between 4LO switch terminals 12 and 13.











5) If the inspection results are not normal replace the 4LO switch.