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                        | Last Modified: 08-21-2023 | 6.11:8.1.0 | Doc ID: RM100000001B4DW |  
                        | Model Year Start: 2019 | Model: Avalon HV | Prod Date Range: [04/2018 -                    
                                       ] |  
                        | Title: A25A-FXS (ENGINE CONTROL): SFI SYSTEM: P26CA31; Engine Coolant Pump No Signal; 2019 - 2022 MY Avalon HV [04/2018 -        ] |  
                     
                        
                           | DTC | P26CA31 | Engine Coolant Pump No Signal |  DESCRIPTIONRefer to DTC P26CA12. Click here
                        
                           
                              ![2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: P26CA12; Engine Coolant Pump Circuit Short to Battery+](/t3Portal/stylegraphics/info.gif)  
                     
                        
                        
                        
                        
                        
                        
                        
                     
                     
                        
                           | DTC No. | Detection Item | DTC Detection Condition | Trouble Area | MIL | Memory | Note |  
                           | P26CA31 | Engine Coolant Pump No Signal | The speed of the water inlet housing with water pump sub-assembly calculated from the WPI signal is less than 10 rpm (open or short in the WPI circuit) (1 trip detection logic). | 
                                 
                                    
Open or short in water inlet housing with water pump sub-assembly circuit
Water inlet housing with water pump sub-assembly
EFI-MAIN NO. 3 relay
ECM
 | Comes on | DTC stored | SAE Code: P26CA |  Related Data List
                     
                        
                        
                     
                     
                        
                           | DTC No. | Data List |  
                           | P26CA31 | 
                                 
                                    
Coolant Temperature
Electric Water Pump Target Speed
Electric Water Pump Speed
 |  MONITOR DESCRIPTIONThe ECM receives a frequency signal (WPI) from the water inlet housing with water pump sub-assembly and calculates the speed of the water inlet housing with water pump sub-assembly. As the frequency signal (WPI) is 4 Hz when the water inlet housing with water pump sub-assembly is stopped to enable the ECM to detect an open or short in the signal line, the water inlet housing with water pump sub-assembly speed will be displayed as approximately 160 rpm even when the pump is stopped. If the water inlet housing with water pump sub-assembly speed is calculated to be less than 10 rpm, the ECM judges that there is an open or short in the WPI circuit and stores this DTC. MONITOR STRATEGY
                     
                        
                        
                     
                     
                        
                           | Related DTCs | P26CA: Engine water pump circuit verify pulse input |  
                           | Required Sensors/Components (Main) | Water inlet housing with water pump sub-assembly |  
                           | Required Sensors/Components (Related) | - |  
                           | Frequency of Operation | Continuous |  
                           | Duration | 15 seconds |  
                           | MIL Operation | Immediate |  
                           | Sequence of Operation | None |  TYPICAL ENABLING CONDITIONS
                     
                        
                        
                     
                     
                        
                           | Monitor runs whenever the following DTCs are not stored | None |  
                           | All of the following conditions are met | - |  
                           | Auxiliary battery voltage | 8 V or higher |  
                           | Power switch | On (IG) |  
                           | Time after power switch off to on (IG) | 0.5 seconds or more |  TYPICAL MALFUNCTION THRESHOLDS
                     
                        
                        
                     
                     
                        
                           | Engine water pump speed | Less than 10 rpm |  CONFIRMATION DRIVING PATTERN
                     HINT: 
                        
After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
Click here
                                 
                                    
                                       ![2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif) 
When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
Click here
                                 
                                    
                                       ![2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: DTC CHECK / CLEAR](/t3Portal/stylegraphics/info.gif)  
                     
                        
Connect the Techstream to the DLC3.
Turn the power switch on (IG).
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 at least 30 seconds.
Turn the power switch on (IG) [A].
Turn the Techstream on.
Put the engine in Inspection Mode (Maintenance Mode).
Click here
                                 
                                    
                                       ![2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; INTRODUCTION: REPAIR INSTRUCTION: INSPECTION MODE PROCEDURE](/t3Portal/stylegraphics/info.gif) 
Start the engine and maintain the engine speed at 2500 rpm or more for at least 40 seconds [B].
Enter the following menus: Powertrain / Engine / Trouble Codes [C].
Read the pending DTCs.
                              HINT: 
                                 
If a pending DTC is output, the system is malfunctioning.
If a pending DTC is not output, perform the following procedure.
Enter the following menus: Powertrain / Engine / Utility / All Readiness.
Input the DTC: P26CA31.
Check the DTC judgment result.
                              
                                 
                                 
                              
                              
                                 
                                    | Techstream Display | Description |  
                                    | NORMAL | 
                                          
                                             
DTC judgment completed
System normal
 |  
                                    | ABNORMAL | 
                                          
                                             
DTC judgment completed
System abnormal
 |  
                                    | INCOMPLETE | 
                                          
                                             
DTC judgment not completed
Perform driving pattern after confirming DTC enabling conditions
 |  WIRING DIAGRAMRefer to DTC P26CA12. Click here
                        
                           
                              ![2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): SFI SYSTEM: P26CA12; Engine Coolant Pump Circuit Short to Battery+](/t3Portal/stylegraphics/info.gif)  CAUTION / NOTICE / HINTHINT: Read Freeze Frame Data using the Techstream. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. When troubleshooting, Freeze Frame Data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred. PROCEDURE
                     
                        
                           | 1.  | CHECK TERMINAL VOLTAGE (POWER SOURCE OF WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) |    
                     
                        
                        
                     
                     
                        
                           | *a | Front view of wire harness connector (to Water Inlet Housing with Water Pump Sub-assembly) |  (a) Disconnect the water inlet housing with water pump sub-assembly connector. (b) Turn the power switch on (IG). (c) Measure the voltage according to the value(s) in the table below. Standard Voltage:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | C39-5 (NWP) - Body ground | Power switch on (IG) | 11 to 14 V |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 2.  | CHECK HARNESS AND CONNECTOR (WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY - BODY GROUND) |  (a) Disconnect the water inlet housing with water pump sub-assembly connector. (b) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | C39-3 (PGN2) - Body ground | Always | Below 1 Ω |  
                           | C39-6 (PGND) - Body ground | Always | Below 1 Ω |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 3.  | CHECK TERMINAL VOLTAGE (POWER SOURCE OF WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) |    
                     
                        
                        
                     
                     
                        
                           | *a | Front view of wire harness connector (to Water Inlet Housing with Water Pump Sub-assembly) |  (a) Disconnect the water inlet housing with water pump sub-assembly connector. (b) Turn the power switch on (IG). (c) Measure the voltage according to the value(s) in the table below. Standard Voltage:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | C39-1 (+B2) - Body ground | Power switch on (IG) | 11 to 14 V |  
                           | C39-4 (+B) - Body ground | Power switch on (IG) | 11 to 14 V |  
                     
                        | 
                              
                                 | NG |  
                                 |   |  |  
                     
                        
                           | 4.  | INSPECT EFI-MAIN NO. 3 RELAY |  (a) Inspect the EFI-MAIN NO. 3 relay. Click here
                        
                           
                              ![2019 - 2022 MY Avalon HV [04/2018 -        ]; A25A-FXS (ENGINE CONTROL): RELAY: ON-VEHICLE INSPECTION+](/t3Portal/stylegraphics/info.gif)  
                     
                        
                           | NG |   | REPLACE EFI-MAIN NO. 3 RELAY |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 5.  | CHECK HARNESS AND CONNECTOR (POWER SOURCE OF EFI-MAIN NO. 3 RELAY) |    
                     
                        
                        
                     
                     
                        
                           | *1 | No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly |  
                           | *2 | EFI-MAIN NO. 3 Relay |  (a) Remove the EFI-MAIN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly. (b) Measure the voltage according to the value(s) in the table below. Standard Voltage:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 3 (EFI-MAIN NO. 3 relay) - Body ground | Always | 11 to 14 V |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR (AUXILIARY BATTERY - EFI-MAIN NO. 3 RELAY) |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 6.  | CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - BODY GROUND) |  (a) Remove the EFI-MAIN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly. (b) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 1 (EFI-MAIN NO. 3 relay) - Body ground | Always | Below 1 Ω |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 7.  | CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 3 RELAY - WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY) |  (a) Remove the EFI-MAIN NO. 3 relay from the No. 1 engine room relay block and No. 1 junction block assembly. (b) Disconnect the water inlet housing with water pump sub-assembly connector. (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | 5 (EFI-MAIN NO. 3 relay) - C39-1 (+B2) | Always | Below 1 Ω |  
                           | 5 (EFI-MAIN NO. 3 relay) - C39-4 (+B) | Always | Below 1 Ω |  
                           | 5 (EFI-MAIN NO. 3 relay), C39-1 (+B2) or C39-4 (+B) - Body ground and other terminals | Always | 10 kΩ or higher |  
                     
                        
                           | OK |   | REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - EFI-MAIN NO. 3 RELAY) |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  
                     
                        
                           | 8.  | CHECK HARNESS AND CONNECTOR (WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY - ECM) |  (a) Disconnect the water inlet housing with water pump sub-assembly connector. (b) Disconnect the ECM connector. (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | C39-5 (NWP) - C55-51 (WPI) | Always | Below 1 Ω |  
                           | C39-5 (NWP) or C55-51 (WPI) - Body ground and other terminals | Always | 10 kΩ or higher |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR |  |