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                        | Last Modified: 08-21-2023 | 6.11:8.1.0 | Doc ID: RM100000001A0FO |  
                        | Model Year Start: 2019 | Model: Avalon HV | Prod Date Range: [04/2018 - 08/2020] |  
                        | Title: HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C8679; Transmission (Input) Mechanical Linkage Failure; 2019 - 2020 MY Avalon HV [04/2018 - 08/2020] |  
                     
                        
                           | DTC | P1C8679 | Transmission (Input) Mechanical Linkage Failure |  DTC SUMMARYRefer to the DTC summary for DTC P1C7779. Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  DESCRIPTIONRefer to the description for DTC P1C7779. Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  
                     
                        
                        
                        
                        
                        
                        
                     
                     
                        
                           | DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Warning Indicate |  
                           | P1C8679 | Transmission (Input) Mechanical Linkage Failure | Hybrid vehicle transaxle malfunction (input system lock): When the vehicle is stopped, an engine cranking signal is sent but the generator (MG1) does not rotate. The generator (MG1) or the engine does not rotate, or the planetary gear unit is malfunctioning. (1 trip detection logic) | 
                                 
                                    
Hybrid vehicle transaxle assembly
Transmission input damper assembly
Engine
 | Does not come on | Master Warning Light: Comes on |  Related Data List
                     
                        
                        
                     
                     
                        
                           | DTC No. | Data List |  
                           | P1C8679 | 
                                 
                                    
Generator Revolution
Motor Revolution
Engine Speed
 |  CONFIRMATION DRIVING PATTERNHINT: After repair has been completed, clear the DTCs and then check that the vehicle has returned to normal by performing the following All Readiness check procedure. Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): UTILITY](/t3Portal/stylegraphics/info.gif)  
                     
                        
Connect the Techstream to the DLC3.
Turn the power switch on (IG) and turn the Techstream on.
Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
Turn the power switch off and wait for 2 minutes or more.
Turn the power switch on (IG) and turn the Techstream on.
With the vehicle stopped and the shift lever in P, turn the power switch on (READY) and gradually depress the accelerator pedal so that the engine starts.
Enter the following menus: Powertrain / Hybrid Control / Utility / All Readiness.
Check the DTC judgment result.
                              HINT: 
                                 
If the judgment result shows NORMAL, the system is normal.
If the judgment result shows ABNORMAL, the system has a malfunction.
If the judgment result shows INCOMPLETE or N/A, perform driving pattern again.
 CAUTION / NOTICE / HINTHINT: If this DTC is output, the engine or gears in the transaxle may have seized. Before performing this inspection, check the engine oil, hybrid transaxle fluid, coolant (for Engine) and coolant (for Inverter) levels. PROCEDURE
                     
                        
                           | 1.  | CHECK DTC OUTPUT (HYBRID CONTROL) |  (a) Connect the Techstream to the DLC3. (b) Turn the power switch on (IG). (c) Enter the following menus: Powertrain / Hybrid Control / Trouble Codes. Powertrain > Hybrid Control > Trouble Codes(d) Check for DTCs. 
                     
                        
                           | Result | Proceed to |  
                           | P1C8679 only is output, or DTCs except the ones in the table below are also output | A |  
                           | Any of the following DTCs including pending DTCs are also output | B |  
                     
                        
                        
                        
                     
                     
                        
                           | Malfunction Content | Relevant DTC |  
                           | Sensor and actuator circuit malfunction | P1C8779 | Generator Mechanical Linkage Failure |  
                           | P1C8879 | Planetary Gear Mechanical Linkage Failure |  HINT: P1C8679 may be output as a result of the malfunction indicated by the DTCs above. (e) Turn the power switch off. 
                     
                        | 
                              
                                 | A |  
                                 |   |  |  
                     
                        
                           | 2.  | CHECK CRANKSHAFT PULLEY REVOLUTION (P POSITION) |  Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  
                     
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                                 | NEXT |  
                                 |   |  |  Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  
                     
                        
                           | Result | Proceed to |  
                           | The absolute value of the difference is less than 500 rpm. | A |  
                           | The absolute value of the difference is 500 rpm or more continuously for 1 second. | B |  
                     
                        
                           | 7.  | CHECK CRANKSHAFT PULLEY REVOLUTION (N POSITION) |  Click here
                        
                           
                              ![2019 - 2020 MY Avalon HV [04/2018 - 08/2020]; HYBRID / BATTERY CONTROL: HYBRID CONTROL SYSTEM (for NICKEL METAL HYDRIDE BATTERY): P1C7779; Engine Failed to Start Mechanical Linkage Failure+](/t3Portal/stylegraphics/info.gif)  
                     
                        
                           | NG |   | REPAIR OR REPLACE ENGINE |  |