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                        | Last Modified: 11-20-2023 | 6.11:8.1.0 | Doc ID: RM1000000012T3J |  
                        | Model Year Start: 2018 | Model: Camry | Prod Date Range: [03/2017 -                    
                                       ] |  
                        | Title: NETWORKING: CAN COMMUNICATION SYSTEM: Main Body ECU Communication Stop Mode; 2018 - 2024 MY Camry [03/2017 -        ] |  
                     
                        
                           | Main Body ECU Communication Stop Mode |  DESCRIPTION
                     
                        
                        
                        
                     
                     
                        
                           | Detection Item | Symptom | Trouble Area |  
                           | Main Body ECU Communication Stop Mode | Any of the following conditions are met: | 
                                 
                                    
Main body ECU (multiplex network body ECU) branch line or connector
Power source circuit of main body ECU (multiplex network body ECU) or instrument panel junction block assembly
Main body ECU (multiplex network body ECU) or instrument panel junction block assembly ground circuit
Main body ECU (multiplex network body ECU) or instrument panel junction block assembly
 |  WIRING DIAGRAM  CAUTION / NOTICE / HINTCAUTION: When performing the confirmation driving pattern, obey all speed limits and traffic laws. 
                     HINT: 
                        
Before disconnecting related connectors for inspection, push in on each connector body to check that the connector is not loose or disconnected.
When a connector is disconnected, check that the terminals and connector body are not cracked, deformed or corroded.
 PROCEDURE
                     
                        
                           | 1.  | CHECK FOR OPEN IN CAN BUS LINES (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) BRANCH LINE) |  (a) Disconnect the cable from the negative (-) battery terminal. (b) Disconnect the K52 main body ECU (multiplex network body ECU) connector. 
                     
                        
                           | (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                                 
                                 
                                 
                                 
                                    
                                       | Tester Connection | Condition | Specified Condition |  
                                       | K52-5 (CANH) - K52-4 (CANL) | Cable disconnected from negative (-) battery terminal | 54 to 69 Ω |  | 
                                 
                                    |   |  
                                    | 
                                          
                                             
                                             
                                          
                                          
                                             
                                                | *a | Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) |  |  |  
                     
                        
                           | NG |   | REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)) |  
                     
                        | 
                              
                                 | OK |  
                                 |   |  |  
                     
                        
                           | 2.  | CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) |  (a) Remove the main body ECU (multiplex network body ECU). Click here
                        
                           
                              ![2018 MY Camry [03/2017 - 06/2017]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL](/t3Portal/stylegraphics/info.gif)  ![2018 - 2020 MY Camry [06/2017 - 10/2020]; POWER DISTRIBUTION: MAIN BODY ECU: REMOVAL](/t3Portal/stylegraphics/info.gif)  ![2021 - 2024 MY Camry [10/2020 -        ]; 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 |  
                                       | MB-11 (GND1) - Body ground | Cable disconnected from negative (-) battery terminal | Below 1 Ω |  NOTICE: Perform this inspection with the wire harness connected to the instrument panel junction block assembly. | 
                                 
                                    |   |  
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                                                | *a | Front view of wire harness connector (to Main Body ECU (Multiplex Network Body ECU)) |  |  |  (c) Reconnect the cable to the negative (-) battery terminal. (d) Measure the voltage according to the value(s) in the table below. Standard Voltage:  
                     
                        
                        
                        
                     
                     
                        
                           | Tester Connection | Condition | Specified Condition |  
                           | MB-30 (ACC) - Body ground | Ignition switch ACC | 11 to 14 V |  
                           | MB-31 (BECU) - Body ground | Always | 11 to 14 V |  
                           | MB-32 (IG) - Body ground | Ignition switch ON | 11 to 14 V |  NOTICE: Perform this inspection with the wire harness connected to the instrument panel junction block assembly. 
                     
                        
                           | Result | Proceed to |  
                           | OK | A |  
                           | NG (BECU) | B |  
                           | NG (ACC) | C |  
                           | NG (IG) | D |  
                           | NG (GND1) | E |  
                     
                        | 
                              
                                 | B |  
                                 |   |  |  
                     
                        
                           | 3.  | CHECK HARNESS AND CONNECTOR (BECU SIGNAL CIRCUIT) |  (a) Disconnect the cable from the negative (-) battery terminal. (b) Disconnect the 3C instrument panel junction block assembly connector. (c) Reconnect the cable to the negative (-) battery terminal. 
                     
                        
                           | (d) Measure the voltage according to the value(s) in the table below. Standard Voltage:  
                                 
                                 
                                 
                                 
                                    
                                       | Tester Connection | Condition | Specified Condition |  
                                       | 3C-1 - Body ground | Always | 11 to 14 V |  | 
                                 
                                    |   |  
                                    | 
                                          
                                             
                                             
                                          
                                          
                                             
                                                | *a | Front view of wire harness connector (to Instrument Panel Junction Block Assembly) |  |  |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR (BECU SIGNAL CIRCUIT) |  
                     
                        
                           | 4.  | CHECK HARNESS AND CONNECTOR (GROUND CIRCUIT) |  (a) Disconnect the cable from the negative (-) battery terminal. (b) Disconnect the 3B instrument panel junction block assembly connector. 
                     
                        
                           | (c) Measure the resistance according to the value(s) in the table below. Standard Resistance:  
                                 
                                 
                                 
                                 
                                    
                                       | Tester Connection | Condition | Specified Condition |  
                                       | 3B-3 - Body ground | Cable disconnected from negative (-) battery terminal | Below 1 Ω |  | 
                                 
                                    |   |  
                                    | 
                                          
                                             
                                             
                                          
                                          
                                             
                                                | *a | Front view of wire harness connector (to Instrument Panel Junction Block Assembly) |  |  |  
                     
                        
                           | NG |   | REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT) |  |