DTC B2439-49: Headlight LH Circuit Internal Electronic Failure; DTC B243A-49: Headlight RH Circuit Internal Electronic Failure [06/2020 - 12/2021]: Procedure
- CHECK FOR DTC
- Check for DTCs.
Body Electrical > Main Body > Trouble Codes
OK
DTC B2439-49 and B243A-49 are not output.
Result
Result Proceed to OK A NG (DTC B2439-49 is output) B NG (DTC B243A-49 is output) C
Result:
A
USE SIMULATION METHOD TO CHECK. Refer to HOW TO PROCEED WITH TROUBLESHOOTING [06/2020 - ]
Result:
C
See step 11
Result:
B
See step 2
- Check for DTCs.
- CHECK HEADLIGHT UNIT ASSEMBLY LH (LO TERMINAL VOLTAGE)
- Disconnect the headlight unit LH connector.
*a Front view of wire harness connector
(to Headlight Unit LH) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A62-1 (LO) - Body ground Light control switch in HEAD position 11 to 14 V Result
Proceed to OK NG
Result:
NG
See step 6
Result:
OK
See step 3
- Disconnect the headlight unit LH connector.
- CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT LH - BODY GROUND)
- Disconnect the headlight unit LH connector.
*a Front view of wire harness connector
(to Headlight Unit LH) - Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A62-2 (E) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 4
- Disconnect the headlight unit LH connector.
- CHECK HEADLIGHT UNIT LH (S TERMINAL VOLTAGE)
- Disconnect the headlight unit LH connector.
*a Front view of wire harness connector
(to Headlight Unit LH) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A62-6 (S) - Body ground Ignition switch ON 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE HEADLIGHT UNIT LH. Refer to REMOVAL [06/2020 - 12/2021]
Result:
NG
See step 5
- Disconnect the headlight unit LH connector.
- CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT LH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])
- Disconnect the A62 headlight unit LH connector.
- Disconnect the G140 main body ECU (multiplex network body ECU) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A62-6 (S) - G140-12 (LLEW) Always Below 1 Ω A62-6 (S) or G140-12 (LLEW) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL [06/2020 - 12/2021]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (H-LP LH RELAY - HEADLIGHT UNIT LH)
- Remove the H-LP LH relay.
- Disconnect the A62 headlight unit LH connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 3 (H-LP LH relay) - A62-1 (LO) Always Below 1 Ω 3 (H-LP LH relay) or A62-1 (LO) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 7
- INSPECT H-LP LH RELAY
Refer to ON-VEHICLE INSPECTION [06/2020 - ]
Result
Proceed to OK NG Result:
NG
REPLACE H-LP LH RELAY
Result:
OK
See step 8
- CHECK HARNESS AND CONNECTOR (POWER SOURCE - H-LP LH RELAY)
- Remove the H-LP LH relay.
*a Front view of wire harness connector
(to H-LP LH Relay) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition 2 (H-LP LH relay) - Body ground Ignition switch off 11 to 14 V 5 (H-LP LH relay) - Body ground Ignition switch off 11 to 14 V Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 9
- Remove the H-LP LH relay.
- CHECK HARNESS AND CONNECTOR (H-LP LH RELAY - POWER DISTRIBUTION BOX ASSEMBLY)
- Remove the H-LP LH relay.
- Disconnect the 4E power distribution box assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 1 (H-LP LH relay) - 4E-6 Always Below 1 Ω 1 (H-LP LH relay) or 4E-6 - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 10
- CHECK POWER DISTRIBUTION BOX ASSEMBLY
- Remove the power distribution box assembly.
Refer to REMOVAL [06/2020 - 12/2021]
*a Component without harness connected
(Power Distribution Box Assembly)- - - Remove the main body ECU (multiplex network body ECU) from the power distribution box assembly.
Refer to REMOVAL [06/2020 - 12/2021]
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 4E-6 - A-15 (HRLY) Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL [06/2020 - 12/2021]
Result:
NG
REPLACE POWER DISTRIBUTION BOX ASSEMBLY. Refer to REMOVAL [06/2020 - 12/2021]
- Remove the power distribution box assembly.
- CHECK HEADLIGHT UNIT RH (LO TERMINAL VOLTAGE)
- Disconnect the headlight unit RH connector.
*a Front view of wire harness connector
(to Headlight Unit RH) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A61-1 (LO) - Body ground Light control switch in HEAD position 11 to 14 V Result
Proceed to OK NG
Result:
NG
See step 15
Result:
OK
See step 12
- Disconnect the headlight unit RH connector.
- CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT RH - BODY GROUND)
- Disconnect the headlight unit RH connector.
*a Front view of wire harness connector
(to Headlight Unit RH) - Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A61-2 (E) - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 13
- Disconnect the headlight unit RH connector.
- CHECK HEADLIGHT UNIT RH (S TERMINAL VOLTAGE)
- Disconnect the headlight unit RH connector.
*a Front view of wire harness connector
(to Headlight Unit RH) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition A61-6 (S) - Body ground Ignition switch ON 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE HEADLIGHT UNIT RH. Refer to REMOVAL [06/2020 - 12/2021]
Result:
NG
See step 14
- Disconnect the headlight unit RH connector.
- CHECK HARNESS AND CONNECTOR (HEADLIGHT UNIT RH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])
- Disconnect the A61 headlight unit RH connector.
- Disconnect the G140 main body ECU (multiplex network body ECU) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A61-6 (S) - G140-13 (RLEW) Always Below 1 Ω A61-6 (S) or G140-13 (RLEW) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL [06/2020 - 12/2021]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
- CHECK HARNESS AND CONNECTOR (H-LP RH RELAY - HEADLIGHT UNIT RH)
- Remove the H-LP RH relay.
- Disconnect the A61 headlight unit RH connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 3 (H-LP RH relay) - A61-1 (LO) Always Below 1 Ω 3 (H-LP RH relay) or A61-1 (LO) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 16
- INSPECT H-LP RH RELAY
Refer to ON-VEHICLE INSPECTION [06/2020 - ]
Result
Proceed to OK NG Result:
NG
REPLACE H-LP RH RELAY
Result:
OK
See step 17
- CHECK HARNESS AND CONNECTOR (POWER SOURCE - H-LP RH RELAY)
- Remove the H-LP RH relay.
*a Front view of wire harness connector
(to H-LP RH Relay) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition 2 (H-LP RH relay) - Body ground Ignition switch off 11 to 14 V 5 (H-LP RH relay) - Body ground Ignition switch off 11 to 14 V Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 18
- Remove the H-LP RH relay.
- CHECK HARNESS AND CONNECTOR (H-LP RH RELAY - POWER DISTRIBUTION BOX ASSEMBLY)
- Remove the H-LP RH relay.
- Disconnect the 4E power distribution box assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 1 (H-LP RH relay) - 4E-10 Always Below 1 Ω 1 (H-LP RH relay) or 4E-10 - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 19
- CHECK POWER DISTRIBUTION BOX ASSEMBLY
- Remove the power distribution box assembly.
Refer to REMOVAL [06/2020 - 12/2021]
*a Component without harness connected
(Power Distribution Box Assembly)- - - Remove the main body ECU (multiplex network body ECU) from the power distribution box assembly.
Refer to REMOVAL [06/2020 - 12/2021]
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 4E-10 - A-9 (HRY2) Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL [06/2020 - 12/2021]
Result:
NG
REPLACE POWER DISTRIBUTION BOX ASSEMBLY. Refer to REMOVAL [06/2020 - 12/2021]
- Remove the power distribution box assembly.