B278C

NETWORKING: LIN COMMUNICATION SYSTEM: B2287,B278C: LIN Communication Master Malfunction

B2287 - LIN Communication Master Malfunction
B278C - Lost Communication with Power Source Control

DESCRIPTION

* DTC B2287 is stored when there is an open or short circuit or an ECU communication malfunction between the power management control ECU and certification ECU.

* DTC B278C is stored when LIN communication between the certification ECU and power management control ECU stops for 10 seconds or more.

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:
* When using the Techstream with the engine switch off to troubleshoot:
* Connect the Techstream to the vehicle and turn a courtesy light switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.
* Inspect the fuses for circuits related to this system before performing the following inspection procedure.
* Before replacing the certification ECU, refer to the engine immobilizer system Engine Immobilizer System.
HINT
When DTC B2287, B278C and B2785 are output simultaneously, perform troubleshooting for DTC B2785 first B2785.

PROCEDURE

1. CLEAR DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

2. CHECK FOR DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B2287 or B278C is not output.

NG -- CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - POWER MANAGEMENT CONTROL ECU)

OK -- USE SIMULATION METHOD TO CHECK Electronic Circuit Inspection Procedure

3. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the G26 certification ECU connector.

(b) Disconnect the G39 power management control ECU connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - BATTERY AND BODY GROUND)

(a) Disconnect the G39 power management control ECU connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Text in Illustration

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. REPLACE POWER MANAGEMENT CONTROL ECU

(a) Temporarily replace the power management control ECU with a new or normally functioning one Removal.

NEXT -- Continue to next step.

6. CLEAR DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

NEXT -- Continue to next step.

7. CHECK FOR DTC

(a) Check for DTCs Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B2287 or B278C is not output.

NG -- REPLACE CERTIFICATION ECU Removal

OK -- END (POWER MANAGEMENT CONTROL ECU IS DEFECTIVE)