DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - MASTER SWITCH)
CHECK FOR DTC
CHECK FOR DTC
CHECK FOR DTC
REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH)
CHECK FOR DTC
REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY)
CHECK FOR DTC
REPLACE ID CODE BOX (IMMOBILISER CODE ECU)
CHECK FOR DTC
DTC B2785 Communication Malfunction between ECUs Connected by LIN
DESCRIPTION
The certification ECU (smart key ECU assembly) intermittently monitors the LIN communication bus between the components related to certification. DTC B2785 is output when a malfunction in the LIN communication bus between the components related to certification is detected continuously 3 times.
| DTC Code | DTC Detection Condition | Trouble Area |
| B2785 | The certification ECU (smart key ECU assembly) detects a malfunction in the LIN communication bus between components related to certification continuously 3 times. | Certification ECU (smart key ECU assembly)
Main body ECU (cowl side junction block LH)
ID code box (immobiliser code ECU)
Steering lock ECU
Harness or connector
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- When using the intelligent tester with the ignition switch off to troubleshoot:
- Connect 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.
- When DTC B2785 and B2287 are output simultaneously, perform the troubleshooting for DTC B2785 first.
| 1.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - MASTER SWITCH) |
Disconnect the 2D and E29 ECU connectors.
Measure the resistance and voltage according to the value(s) in the table below.
- Standard Resistance:
| Tester Connection | Condition | Specified Condition |
| E29-10 (LIN) - 2D-20 (LIN1) | Always | Below 1 Ω |
| E29-10 (LIN) - Body ground | Always | 10 kΩ or higher |
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
| Tester Connection | Condition | Specified Condition |
| E29-10 (LIN) - Body ground | Always | Below 1 V |
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
Reconnect the E26 and E29 ECU connectors.
Reconnect the E28 box connector.
Recheck for DTCs.
Result| Result | Proceed to |
| DTC B2785 is output | A |
| DTC B2785 is not output | B |
Reconnect the 2D ECU connector.
Disconnect the E26 ECU connector.
Recheck for DTCs.
Result| Result | Proceed to |
| DTC B2785 is output | A |
| DTC B2785 is not output | B |
Reconnect the E26 ECU connector.
Disconnect the E28 box ECU connector.
Recheck for DTCs.
Result| Result | Proceed to |
| DTC B2785 is output | A |
| DTC B2785 is not output | B |
| A | |
| |
| REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
|
| 5.REPLACE MAIN BODY ECU (COWL SIDE JUNCTION BLOCK LH) |
Temporarily replace the main body ECU (cowl side junction block LH) with a new or normally functioning one.
Recheck for DTCs.
Result| Result | Proceed to |
| DTC B2785 is not output | A |
| DTC B2785 is output | B |
| | REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
|
|
| A | |
| |
| END (MAIN BODY ECU IS DEFECTIVE) |
|
| 7.REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) |
Temporarily replace the steering lock ECU with a new or normally functioning one ().
Recheck for DTCs.
Result| Result | Proceed to |
| DTC B2785 is not output | A |
| DTC B2785 is output | B |
| | REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
|
|
| A | |
| |
| END (STEERING LOCK ECU IS DEFECTIVE) |
|
| 9.REPLACE ID CODE BOX (IMMOBILISER CODE ECU) |
Temporarily replace the ID code box immobiliser code ECU with a new or normally functioning one.
Recheck for DTCs ().
Result| Result | Proceed to |
| DTC B2785 is not output | A |
| DTC B2785 is output | B |
| | REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) |
|
|
| A | |
| |
| END (ID CODE BOX IS DEFECTIVE) |
|
