Back-up Light Circuit [06/2018 - 08/2020]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus ES 300h, 2023 Lexus ES 300h, 2022 Lexus ES 300h, 2021 Lexus ES 300h, and 2020 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK FOR DTC
- Connect the Techstream to the DLC3.
- Turn the power switch on (IG).
- Turn the Techstream on.
- Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.
- Check for DTCs.
Powertrain > Hybrid Control > Trouble Codes
Result
Result Proceed to Hybrid control system DTCs are not output A Hybrid control system DTCs are output B
Result:
B
GO TO HYBRID CONTROL SYSTEM. Refer to DIAGNOSTIC TROUBLE CODE CHART [06/2018 - 08/2021]
Result:
A
See step 2
- CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BODY GROUND)
- Disconnect the 3D instrument panel junction block assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition 3D-3 - Body ground Always Below 1 Ω Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 3
- CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)
- Disconnect the A33 hybrid vehicle control ECU connector.
- Disconnect the 3F instrument panel junction block assembly connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A33-2 (BL) - 3F-19 Always Below 1 Ω A33-2 (BL) or 3F-19 - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 4
- CHECK HYBRID VEHICLE CONTROL ECU (OUTPUT VOLTAGE)
*a Component with harness connected
(Instrument Panel Junction Block Assembly)- Connect the A33 hybrid vehicle control ECU connector.
- Connect the 3D and 3F instrument panel junction block assembly connectors.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition 3F-19 - Body ground Power switch off, reverse (R) not selected Below 1 V 3F-19 - Body ground Power switch on (IG), reverse (R) selected 11 to 14 V Result
Proceed to OK NG
Result:
NG
REPLACE HYBRID VEHICLE CONTROL ECU. Refer to REMOVAL [06/2018 - 08/2021]
Result:
OK
See step 5
- INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (OUTPUT VOLTAGE)
*a Component with harness connected
(Instrument Panel Junction Block Assembly)- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition 3H-10 - Body ground Power switch off, reverse (R) not selected Below 1 V 3H-10 - Body ground Power switch on (IG), reverse (R) selected 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to REMOVAL [06/2018 - 08/2021]
- Measure the voltage according to the value(s) in the table below.