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                        | Last Modified: 08-21-2023 | 6.11:8.1.0 | Doc ID: RM100000001AYCN |  
                        | Model Year Start: 2019 | Model: Avalon | Prod Date Range: [04/2018 -                    
                                       ] |  
                        | Title: LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model without Cornering Light): Daytime Running Light Circuit; 2019 - 2022 MY Avalon [04/2018 -        ] |  
                     
                        
                           | Daytime Running Light Circuit |  DESCRIPTIONThe main body ECU (multiplex network body ECU) controls the daytime running lights. 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 [04/2018 - 08/2020]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)  ![2021 - 2022 MY Avalon [08/2020 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, Gasoline Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)  PROCEDURE
                     
                        
                           | 1.  | CHECK OPERATION (LOW BEAM HEADLIGHTS) |  (a) Check the operation of the low beam headlights. OK:  The low beam headlights operate normally. 
                     
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                                 | OK |  
                                 |   |  |  
                     
                        
                           | 2.  | PERFORM ACTIVE TEST USING TECHSTREAM |  (a) Connect the Techstream to the DLC3. (b) Turn the engine 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 |  
                           | Daytime Running Light | Daytime running lights | OFF or ON | - |  Body Electrical > Main Body > Active Test
                     
                        
                     
                     
                        
                           | Tester Display |  
                           | Daytime Running Light |  OK:  Daytime running lights illuminate. 
                     
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                                 | NG |  
                                 |   |  |  (a) Inspect the DRL relay. Click here
                        
                           
                              ![2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; LIGHTING (EXT): RELAY: ON-VEHICLE INSPECTION](/t3Portal/stylegraphics/info.gif)  
                     
                        
                           | NG |   | REPLACE DRL RELAY |  
                     
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                                 | OK |  
                                 |   |  |  
                     
                        
                           | 4.  | CHECK HARNESS AND CONNECTOR (POWER SOURCE - DRL RELAY) |  (a) Measure the voltage according to the value(s) in the table below. Standard Voltage:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 1 (DRL relay) - Body ground | Always | 11 to 14 V |  
                           | 3 (DRL relay) - Body ground | Always | 11 to 14 V |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  
                     
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                                 | OK |  
                                 |   |  |  
                     
                        
                           | 5.  | CHECK HARNESS AND CONNECTOR (DRL RELAY - HEADLIGHT ASSEMBLY) |  (a) Disconnect the A45 headlight assembly LH connector. (b) Disconnect the A44 headlight assembly RH connector. (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 5 (DRL relay) - A45-1 (B) | Always | Below 1 Ω |  
                           | 5 (DRL relay) - A44-1 (B) | Always | Below 1 Ω |  
                           | 5 (DRL relay) or A45-1 (B) - Body ground | Always | 10 kΩ or higher |  
                           | 5 (DRL relay) or A44-1 (B) - Body ground | Always | 10 kΩ or higher |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  
                     
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                                 | OK |  
                                 |   |  |  
                     
                        
                           | 6.  | CHECK HARNESS AND CONNECTOR (DRL RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) |  (a) Disconnect the 4F instrument panel junction block assembly connector. (b) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 2 (DRL relay) - 4F-28 | Always | Below 1 Ω |  
                           | 2 (DRL relay) or 4F-28 - Body ground | Always | 10 kΩ or higher |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 7.  | 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) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 4F-28 - MB-25 (DRL) | Always | Below 1 Ω |  |