1. INSPECT DIFFERENTIAL LOCK SYSTEM
(a) Inspect the indicator light.
Check that the indicator light lights up for approx. 1 second when the ignition switch is turned ON.
(b) Inspect the differential lock operation.
Differential lock is applied to the rear wheel at this time.
HINT: If the gears of the differential lock system are not meshed, the indicator light remains blinking, so rotate the tires to mesh the gear.
Differential lock is released for the rear wheel at this time.
2. INSPECT DIFF. LOCK SYSTEM CIRCUIT
(a) Inspect the battery positive voltage.
Battery positive voltage: 10 - 14 V
(b) Inspect the system circuit with the connector disconnected.
Disconnect the connector from the rear diff. lock control ECU and inspect the connector on the wire harness side, as shown in the table.
HINT: If the circuit is not as specified value, check and repair or replace the trouble part shown in the table above.
(c) Inspect the system circuit with the connector connected.
*: The rear differential should be locked mechanically.
If the circuit is not as specified value, replace the ECU.
3. INSPECT DIFF. LOCK COMPONENTS
(a) Inspect the relay operation.
NOTICE: Connect the terminals being careful not to touch the neighboring terminals or metallic parts of the relay housing.
If operation is not as specified, replace the actuator.
(b) Inspect the diff. lock control switch continuity.
Inspect the switch continuity between terminal 1 to terminal 4.
HINT: If continuity dose not exist, replace the switch.
(c) Inspect the diff. lock indicator switch.
HINT: If operation is not as specified, replace the switch.
(d) Inspect the L position switch ( TR-49 ).
(e) Inspect the vehicle speed sensor ( BE-63 ).