Refer to "64.Body Control 10I.Troubleshooting(BCM) diagnostic system check-body controls".
1) Connect the scan tool.
2) Turn OFF the ignition switch.
3) Turn ON the ignition switch.
4) Operate the light control switch to the low beam position.
5) Observe the DTC information with a scan tool. Is a DTC set?
Yes
=>Go to LED headlight inspection.
No
Go to Intermittent conditions of body control system.
Refer to "223.Body Control 36D.Symptom(BCM) intermittent conditions of body control system".
1) Inspect the LED headlight for the following. Is the result normal?
Yes
=>Go to LED headlight (left) low beam output circuit inspection.
No
Repair or replace as necessary.
1) Disconnect the following harness connector.
2) Inspect the LED headlight (left) low beam output circuit between the BCM (pin 12 of C18) and the LED headlight (pin 2 of C29) for the following. Is the result normal?
Refer to "LHD Body Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 with DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 without DPD, RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to Inspection for open circuit in LED headlight (left) low beam ground circuit.
No
Repair the circuit as necessary.
1) Inspect the ground circuit between the LED headlight (pin 3 of C29) and the body ground for an open circuit or high resistance. Is the result normal?
Refer to "LHD Body Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 with DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 without DPD, RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to LED headlight (left) harness connector inspection.
No
Repair the circuit as necessary.
1) Inspect for poor connections at the LED headlight (left) harness connector (pins 2 and 3 of C28). Is the connection status normal?
Refer to "LHD Body Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 with DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 without DPD, RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
=>Go to BCM harness connector inspection.
No
Repair the connections as necessary.
1) Inspect for poor connections at the BCM harness connector (pin 12 of C18). Is the connection status normal?
Refer to "LHD Body Control" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 with DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Refer to "RHD Body Control (4JJ3 without DPD, RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).
Yes
Replace the LED headlight (left).
Refer to "9.Body, Cab, Accessories 9A.Lighting Systems headlight removal".
Refer to "9.Body, Cab, Accessories 9A.Lighting Systems headlight installation".
=>Go to Current DTC follow-up check.
No
Repair the connections as necessary.
1) Clear the DTC with a scan tool.
2) Turn OFF the ignition switch for 30 seconds or more.
3) Turn ON the ignition switch.
4) Operate the light control switch to the low beam position.
5) Observe the DTC information with a scan tool. Is a DTC set?
Yes
No
Note
Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM removal".
Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM installation".
Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM setting".
Procedure completion
1) Clear the DTC with a scan tool.
2) Turn OFF the ignition switch for 30 seconds or more.
3) Turn ON the ignition switch.
4) Operate the light control switch to the low beam position.
5) Observe the DTC information with a scan tool.