B2785

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2785: Communication Malfunction between ECUs Connected by LIN

DTC B2785 - Communication Malfunction between ECUs Connected by LIN

DESCRIPTION

This DTC is output when LIN communication from the certification ECU stops for a certain amount of time.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK FOR DTC
(a) Delete the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Check for DTC.
OK:
DTC B2785 output does not reoccur.
OK -- NORMAL
NG -- Continue to next step.
2. CHECK WIRE HARNESS (LIN COMMUNICATION LINE)





(a) Disconnect the U28, K28 and K73 ECU connectors.
(b) Disconnect the K58 box and connector.
(c) Measure the resistance of the wire harness side connectors.
HINT: Perform the LIN communication wire harness inspection in the following order: certification ECU, power source control ECU, steering lock ECU, ID code box.

Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK CERTIFICATION ECU (OPERATION)
(a) Temporarily replace the certification ECU with a new or normally functioning one.
(b) Check for DTC.
OK:
DTC B2785 output does not reoccur.
OK -- END (CERTIFICATION ECU IS DEFECTIVE)
NG -- Continue to next step.
4. CHECK POWER SOURCE CONTROL ECU (OPERATION)
(a) Temporarily replace the power source control ECU with a new or normally functioning one.
(b) Check for DTC.
OK:
DTC B2785 output does not reoccur.
OK -- END (POWER SOURCE CONTROL ECU IS DEFECTIVE)
NG -- Continue to next step.
5. CHECK STEERING ACTUATOR ASSEMBLY (OPERATION)
(a) Temporarily replace the steering actuator (steering lock ECU) with a new or normally functioning one Removal.
(b) Check for DTC.
OK:
DTC B2785 output does not reoccur.
NG -- REPLACE ID CODE BOX
OK -- END (STEERING LOCK ECU IS DEFECTIVE)