B2785
NETWORKING: LIN COMMUNICATION SYSTEM: B2785: Communication Malfunction between ECUs Connected by LIN
B2785 - Communication Malfunction between ECUs Connected by LIN
DESCRIPTION
The certification ECU (smart key ECU assembly) monitors communication between all the ECUs connected to the certification bus lines. When the certification ECU (smart key ECU assembly) detects errors in communication with all the ECUs connected to the certification bus lines at a set interval and 3 times in a row, DTC B2785 will be stored.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* If the certification ECU (smart key ECU assembly) is replaced, register the keys Engine Immobilizer System.
* If the steering lock ECU (steering lock actuator assembly) is replaced, register the ECU code Engine Immobilizer System.
* If the ID code box (immobilizer code ECU) is replaced, register the ECU code and ECU communication ID Engine Immobilizer System.
* When using the Techstream with the engine switch off to troubleshoot:
Connect the Techstream to the vehicle, and turn the courtesy light switch on and off at 1.5-second intervals until communication between the Techstream and the vehicle begins.
PROCEDURE
1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - EACH ECU)
(a) Disconnect the P33, J55, J69 and J29 connectors.
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard Resistance:
Standard Voltage:
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. CHECK DTC OUTPUT (POWER SOURCE CONTROL ECU)
(a) Reconnect the P33, J29 and J69 connectors.
(b) Clear the DTC LIN Communication System.
(c) Recheck for DTCs.
Result:
B -- REPLACE POWER SOURCE CONTROL ECU Removal
A -- Continue to next step.
3. CHECK DTC OUTPUT (STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY))
(a) Reconnect the J55 connector.
(b) Disconnect the J29 connector.
(c) Clear the DTC LIN Communication System.
(d) Recheck for DTCs.
Result:
B -- REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) Removal
A -- Continue to next step.
4. CHECK DTC OUTPUT (ID CODE BOX (IMMOBILIZER CODE ECU))
(a) Reconnect the J29 connector.
(b) Disconnect the J69 connector.
(c) Clear the DTC LIN Communication System.
(d) Recheck for DTCs.
Result:
B -- REPLACE ID CODE BOX (IMMOBILIZER CODE ECU) Removal
A -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal