Low Beam Headlight Circuit [09/2019 - 08/2020]: Procedure
- PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT RELAY)
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Enter the following menus: Body Electrical / Main Body / Active Test.
- Check that the relay operates.
Body Electrical > Main Body > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Headlight Relay Low beam headlights ON or OFF - Body Electrical > Main Body > Active Test
Tester Display Headlight Relay OK
Headlight relay operates. (Low beam headlights illuminate.)
Result
Proceed to OK NG
Result:
OK
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to PROBLEM SYMPTOMS TABLE [09/2019 - 08/2020]
Result:
NG
See step 2
- INSPECT NO. 1 INTEGRATION RELAY (H-LP LH RELAY, H-LP RH RELAY)
- Remove the No. 1 integration relay from the No. 1 engine room relay block.
Refer to REMOVAL [02/2017 - 08/2020]
- Inspect the No. 1 integration relay.
Refer to INSPECTION [02/2017 - ]
OK
No. 1 integration relay is normal.
Result
Proceed to OK NG
Result:
NG
REPLACE NO. 1 INTEGRATION RELAY. Refer to REMOVAL [02/2017 - 08/2020]
Result:
OK
See step 3
- Remove the No. 1 integration relay from the No. 1 engine room relay block.
- CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - BATTERY)
- Measure the voltage according to the value(s) in the chart below.
Standard Voltage
Tester Connection Condition Specified Condition 1A-5 - Body ground Always 11 to 14 V 1B-8 - Body ground Always 11 to 14 V *a Rear view of wire harness connectors
(to No. 1 integration relay)*b H-LP LH Relay terminal *c H-LP RH Relay terminal Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 4
- Measure the voltage according to the value(s) in the chart below.
- CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - HEADLIGHT ASSEMBLY LH AND HEADLIGHT ASSEMBLY RH AND BODY GROUND)
- Disconnect the A9 headlight assembly LH connector.
- Disconnect the A28 headlight assembly RH connector.
- Measure the resistance according to the value(s) in the chart below.
Standard Resistance
Tester Connection Condition Specified Condition 1B-1 - A9-2 (LO) Always Below 1 Ω 1A-12 - A28-2 (LO) Always Below 1 Ω A9-1 (E) - Body ground Always Below 1 Ω A28-1 (E) - Body ground Always Below 1 Ω 1B-1 - Body ground Always 10 kΩ or higher 1A-12 - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 5
- CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK)
- Disconnect the 3F instrument panel junction block assembly connector.
- Measure the resistance according to the value(s) in the chart below.
Standard Resistance
Tester Connection Condition Specified Condition 1A-11 - 3F-31 Always Below 1 Ω 1B-2 - 3F-31 Always Below 1 Ω 1A-11 or 3F-31 - Body ground Always 10 kΩ or higher 1B-2 or 3F-31 - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 6
- INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
- Remove the instrument panel junction block assembly.
Refer to REMOVAL [10/2017 - 08/2020]
- Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
- Measure the resistance according to the value(s) in the chart below.
*a Component without harness connected
(Instrument Panel Junction Block Assembly)- - Standard Resistance
Tester Connection Condition Specified Condition 3F-31 - MB-15 (HRLY) Always Below 1 Ω Result
Proceed to OK NG
Result:
OK
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to REMOVAL [10/2017 - 08/2020]
Result:
NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to REMOVAL [10/2017 - 08/2020]
- Remove the instrument panel junction block assembly.