B1278

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1278: Combination Switch ECU Communication Stop
B1278 - Combination Switch ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the combination switch (combination switch ECU) and gateway ECU stops for more than 10 seconds.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (COMBINATION SWITCH - BATTERY AND BODY GROUND)

(a) Disconnect the D13 combination switch connector.

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

Voltage:





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

Resistance:





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

2. CHECK RESISTANCE OF COMMUNICATION LINE

(a) Disconnect the D13, D6, and D39*1 or D37*2 ECU connectors.

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

Resistance:





HINT
*1: w/ Smart key system

*2: w/o Smart key system

Result:





C -- REPAIR OR REPLACE HARNESS OR CONNECTOR

B -- REPLACE COMBINATION SWITCH AND REPAIR OR REPLACE HARNESS OR CONNECTOR

A -- REPLACE COMBINATION SWITCH