Taillight Relay Circuit [11/2024 - ]: Procedure
WARNING: This page is about a different car, the 2025 Toyota RAV4, 2024 Toyota RAV4, 2023 Toyota RAV4, and 2022 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
- PERFORM ACTIVE TEST USING TECHSTREAM
- 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.
- Perform the Active Test according to the display on the Techstream.
Body Electrical > Main Body > Active Test
Tester Display Measurement Item Control Range Diagnostic Note Taillight / Clearance Light Taillight relay OFF or ON - Body Electrical > Main Body > Active Test
Tester Display Taillight / Clearance Light OK
Taillights illuminate.
Result
Proceed to OK NG
Result:
OK
PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE
Refer to PROBLEM SYMPTOMS TABLE [12/2021 - ]
Result:
NG
See step 2
- CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - BATTERY)
- Disconnect the instrument panel junction block assembly connector.
*a Front view of wire harness connector
(to Instrument Panel Junction Block Assembly) - Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Switch Condition Specified Condition 4K-1 - 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 3
- Disconnect the instrument panel junction block assembly connector.
- INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
*a Component without harness connected
(Instrument Panel Junction Block Assembly)- - - Remove the instrument panel junction block assembly.
Refer to REMOVAL [10/2023 - ]
- Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
- Connect a positive (+) lead from the auxiliary battery to terminal 4K-1.
- Connect a negative (-) lead from the auxiliary battery to terminal A-14 (TRLY).
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition 4F-32 - Auxiliary battery negative (-) terminal Auxiliary battery voltage is applied between terminals 4K-1 - A-14 (TRLY) 11 to 14 V 4H-30 - Auxiliary battery negative (-) terminal Auxiliary battery voltage is applied between terminals 4K-1 - A-14 (TRLY) 11 to 14 V Result
Proceed to OK NG
Result:
OK
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
Refer to REMOVAL [10/2023 - ]
Result:
NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
Refer to REMOVAL [10/2023 - ]
- Remove the instrument panel junction block assembly.