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                        | Last Modified: 08-21-2023 | 6.11:8.1.0 | Doc ID: RM100000001AO1G |  
                        | Model Year Start: 2019 | Model: Avalon HV | Prod Date Range: [04/2018 -                    
                                       ] |  
                        | Title: LIGHTING (EXT): LIGHTING SYSTEM (for HV Model without Cornering Light): Taillight Relay Circuit; 2019 - 2022 MY Avalon HV [04/2018 -        ] |  DESCRIPTIONThe main body ECU (multiplex network body ECU) controls the operation of the TAIL relay. WIRING DIAGRAM  CAUTION / NOTICE / HINT
                     NOTICE: 
                        
Inspect the fuses for circuits related to this system before performing the following procedure.
Before replacing the main body ECU (multiplex network body ECU), refer to Registration.
Click here
                                 
                                    
                                       ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)  ![2021 - 2022 MY Avalon HV [08/2020 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)  PROCEDURE
                     
                        
                           | 1.  | PERFORM ACTIVE TEST USING TECHSTREAM |  (a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Turn the Techstream on. (d) Enter the following menus: Body Electrical / Main Body / Active Test. (e) 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 Relay | Taillight relay | OFF or ON | - |  Body Electrical > Main Body > Active Test
                     
                        
                     
                     
                        
                           | Tester Display |  
                           | Taillight Relay |  OK:  Taillights illuminate. 
                     
                        | 
                              
                                 | NG |  
                                 |   |  |  
                     
                        
                           | 2.  | CHECK HARNESS AND CONNECTOR (POWER SOURCE - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) |  (a) Disconnect the 4K instrument panel junction block assembly connector. (b) Measure the voltage according to the value(s) in the table below. Standard Voltage:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 4K-1 - Body ground | Power switch off | 11 to 14 V |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 3.  | INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY |    
                     
                        
                        
                        
                        
                     
                     
                        
                           | *a | Component without harness connected (Instrument Panel Junction Block Assembly) | - | - |  (a) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly. Click here
                        
                           
                              ![2019 - 2021 MY Avalon Avalon HV [04/2018 - 08/2021]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL](/t3Portal/stylegraphics/info.gif)  ![2022 MY Avalon Avalon HV [08/2021 -        ]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL](/t3Portal/stylegraphics/info.gif)  (b) Connect a positive (+) lead from the auxiliary battery to terminal 4K-1. (c) Connect a negative (-) lead from the auxiliary battery to terminal MB-14 (TRLY). (d) 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 | Always | 11 to 14 V |  
                           | 4H-30 - Auxiliary battery negative (-) terminal | Always | 11 to 14 V |  |