LIN Communication System
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 ECU bus lines. When the certification ECU (smart key ECU assembly) detects errors in communication with all the ECUs connected to the certification ECU bus lines at a set interval and 3 times in a row, DTC B2785 will be output.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
* If the certification ECU (smart key ECU assembly) is replaced, register the key 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 (immobiliser code ECU) is replaced, register the ECU code and ECU communication ID Engine Immobilizer System.
PROCEDURE
1. CHECK FOR DTC
(a) Clear the DTC LIN Communication System.
(b) Recheck for DTC.
OK:
B2785 is not output.
NG -- CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - EACH ECU)
OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting
2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - EACH ECU)
(a) Disconnect the P33, J55, J69 and J29 ECU connectors.
(b) Measure the resistance and voltage according to the value(s) in the table below.
Standard Resistance:
Standard Voltage:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK FOR DTC (STEERING LOCK ECU)
(a) Reconnect the P33, J55 and J69 connectors.
(b) Clear the DTC LIN Communication System.
(c) Recheck for DTC.
Result:
B -- REPLACE STEERING LOCK ECU (STEERING LOCK ACTUATOR ASSEMBLY) Disassembly
A -- Continue to next step.
4. CHECK FOR DTC (ID CODE BOX)
(a) Reconnect the J29 connector.
(b) Disconnect the J69 connector.
(c) Clear the DTC LIN Communication System.
(d) Recheck for DTC.
Result:
B -- REPLACE ID CODE BOX (IMMOBILISER CODE ECU) Removal
A -- Continue to next step.
5. REPLACE POWER SOURCE CONTROL ECU
(a) Replace the power source control ECU.
NEXT -- Continue to next step.
6. CHECK FOR DTC
(a) Clear the DTC LIN Communication System.
(b) Recheck for DTC.
OK:
B2785 is not output.
NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal
OK -- END (POWER SOURCE CONTROL ECU IS DEFECTIVE)