DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CLEAR DTC
CHECK FOR DTC
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF ECU)
CHECK SLIDING ROOF ECU (BATTERY VOLTAGE AND BODY GROUND)
REPLACE SLIDING ROOF ECU
CHECK FOR DTC
DTC B1273 Sliding Roof ECU Communication Stop
DESCRIPTION
This DTC is stored when LIN communication between the sliding roof ECU and main body ECU (cowl side junction block LH) stops for 10 seconds or more.
| DTC Code | DTC Detection Condition | Trouble Area |
| B1273 | No communication between the sliding roof ECU and main body ECU (cowl side junction block LH) for 10 seconds or more. | Sliding roof ECU
Main body ECU (cowl side junction block LH)
Harness or connector
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- When using the intelligent tester with the ignition switch off to troubleshoot:
- Connect the intelligent tester to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the intelligent tester and vehicle begins.
- DTC B2325 is stored when the communication between the sliding roof ECU and main body ECU (cowl side junction block LH) stops.
Recheck for DTCs ().
Result| Result | Proceed to |
| DTC B1273 is output | A |
| DTC B1273 is not output | B |
| | USE SIMULATION METHOD TO CHECK ()
|
|
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| 3.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - SLIDING ROOF ECU) |
Disconnect the E3 and R5 ECU connectors.
Measure the resistance and voltage according to the value(s) in the tables below.
- Standard Resistance:
| Tester Connection | Condition | Specified Condition |
| E3-10 (LIN2) - R5-4 (MPX1) | Always | Below 1 Ω |
| E3-10 (LIN2) or R5-4 (MPX1) - Body ground | Always | 10 kΩ or higher |
- Standard Voltage:
| Tester Connection | Condition | Specified Condition |
| R5-4 (MPX1) - Body ground | Always | Below 1 V |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 4.CHECK SLIDING ROOF ECU (BATTERY VOLTAGE AND BODY GROUND) |
Disconnect the R5 ECU connector.
Measure the resistance and voltage according to the value(s) in the tables below.
- Standard Resistance:
| Tester Connection | Condition | Specified Condition |
| R5-2 (E) - Body ground | Always | Below 1 Ω |
- Standard Voltage:
| Tester Connection | Condition | Specified Condition |
| R5-1 (B) - Body ground | Always | 11 to 14 V |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 5.REPLACE SLIDING ROOF ECU |
Temporarily replace the sliding roof ECU with a new or normally functioning one ().
Recheck for DTCs ().
Result| Result | Proceed to |
| DTC B1273 is not output | A |
| DTC B1273 is output | B |
| | REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH) |
|
|
| A | |
| |
| END (SLIDING ROOF ECU IS DEFECTIVE) |
|
