| "Maintenance Required for Traction Battery Cooling Parts See Owner's Manual" is displayed on the multi-information display.* | 1. Make sure the HV battery cooling system intake port is not blocked. | - | 
                        
                           | 2. Make sure there are no gaps between the connecting parts of the ducts. | - | 
                        
                           | 3. Clean the No. 1 HV battery intake filter. Check for entry of foreign matter. | 
                                 
                                    
                                       
                                          ![2019 - 2022 MY Avalon HV [04/2018 -        ]; HYBRID / BATTERY CONTROL: BATTERY COOLING FILTER: INSPECTION](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | 4. Clear the DTCs to reset the learning values even if no DTCs are stored. | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | Abnormal sound is heard from the area around the No. 1 hybrid battery intake duct. | 1. Make sure the HV battery cooling system intake port is not blocked. | - | 
                        
                           | 2. Make sure there are no gaps between the connecting parts of the ducts. | - | 
                        
                           | 3. Clean the No. 1 HV battery intake filter. Check for entry of foreign matter. | 
                                 
                                    
                                       
                                          ![2019 - 2022 MY Avalon HV [04/2018 -        ]; HYBRID / BATTERY CONTROL: BATTERY COOLING FILTER: INSPECTION](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | 4. Clear the DTCs to reset the learning values even if no DTCs are stored. | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | "Have Traction Battery Inspected" is displayed on the multi-information display. | "Have Traction Battery Inspected" is displayed. | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): "HAVE TRACTION BATTERY INSPECTED" is displayed](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | Power switch does not turn on (READY). | Smart Key System (for Start Function) | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Start Function, HV Model): REGISTRATION](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | ECU Power Source Circuit (Hybrid Battery System) | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): ECU Power Source Circuit](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | ECU Power Source Circuit (Hybrid Control System) | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY): ECU Power Source Circuit](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | Check Vehicle Control History (Ready ON Prevention) | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): VEHICLE CONTROL HISTORY](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | The power switch is slow to turn on (READY). | Check Vehicle Control History (Ready ON Prevention) | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): VEHICLE CONTROL HISTORY](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | Engine stops and starts less frequently. | Check Vehicle Control History (Limit to Charge / Discharge Control Value by Hybrid/EV Battery) | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): VEHICLE CONTROL HISTORY](/t3Portal/stylegraphics/info.gif)  | 
                        
                           | Engine speed returns to idle slowly after accelerator pedal is fully released. | Check Vehicle Control History (Limit to Charge / Discharge Control Value by Hybrid/EV Battery) | 
                                 
                                    
                                       
                                          ![2021 - 2022 MY Avalon HV [08/2020 -        ]; HYBRID / BATTERY CONTROL: HYBRID BATTERY SYSTEM (for LITHIUM-ION BATTERY): VEHICLE CONTROL HISTORY](/t3Portal/stylegraphics/info.gif)  |