diagnostic system check - differential lock controls (Differential Lock)

If there are no complaints on drivability, do not perform these diagnostic steps unless otherwise instructed in other sections.
Check for related Service Bulletins before starting the diagnosis.
Do not clear the DTC unless instructed to do so in a diagnostic step.
The battery should be fully charged.
The battery cable should be normal and securely connected.
The ground of the rear differential lock control unit should be securely connected to the correct position.
The rear differential lock control unit harness connector should be clean and correctly connected.
The rear differential lock control unit terminal should be clean and correctly connected.

1. Scan tool power-up check

1) Connect the scan tool. Does the scan tool power up?

Yes

=>Go to Scan tool communication verification.

Go to Scan tool does not power up.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) Scan tool does not power up".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Scan tool does not power up".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Scan tool does not power up".

2. Scan tool communication verification

1) Turn ON the ignition switch.

2) Check the vehicle specifications and verify that communication can be established with the rear differential lock control unit using the scan tool. Can communication with the rear differential lock control unit be established?

Yes

=>Go to DTC verification.

Go to Lost communication with the rear differential lock control unit.

Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) lost communication with the rear differential lock control unit (models with radar sensor/ stereo camera)".

Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) lost communication with the rear differential lock control unit (models without radar sensor and stereo camera)".

3. DTC verification

1) Observe the DTC information for the rear differential lock control unit with a scan tool. Is a DTC set?

Yes

Go to the applicable DTC diagnosis.

=>Go to Rear differential lock failure warning light illumination check.

4. Rear differential lock failure warning light illumination check

1) Turn OFF the ignition switch.

2) Turn ON the ignition switch.

3) Check the rear differential lock failure warning light in the instrument panel cluster. Is the result normal?

Note

After the ignition switch is turned ON, the rear differential lock failure warning light illuminates for approximately 3 seconds, and then turns OFF.

Yes

=>Go to Rear differential lock indicator light illumination check.

Go to Rear differential lock failure warning light illumination circuit system check.

Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) rear differential lock failure warning light illumination circuit system check".

5. Rear differential lock indicator light illumination check

1) Lift up the vehicle.

2) Operate the vehicle in differential lock ON mode and operate the vehicle in differential lock OFF mode.

3) Check the rear differential lock indicator light. Is the result normal?

Note

The rear differential lock indicator light illuminates when the differential lock is operated, and it turns OFF when the differential lock is released.

Yes

=>Go to Customer's concern check.

Go to Rear differential lock indicator light illumination circuit system check.

Refer to "53.Driveline Control 3A.Troubleshooting(Differential Lock) rear differential lock indicator light illumination circuit system check".

6. Customer's concern check

1) Check if the customer's concern is related to the systems other than the differential lock. Is the customer's concern related to the systems other than the differential lock?

Yes

Go to the applicable control system inspection.

=>Go to Symptom check.