B1262

MULTIPLEX COMMUNICATION: MULTIPLEX COMMUNICATION SYSTEM: B1262: A/C ECU Communication Stop

DTC B1262 - A/C ECU Communication Stop

DESCRIPTION

This DTC is detected when communication between the A/C ECU and gateway ECU stops for more than 10 seconds.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK OPERATION
(a) Check that the A/C switch can operate the air conditioner normally.
OK:
A/C switch can operate the air conditioner normally.
OK -- CHECK RESISTANCE OF COMMUNICATION LINE
NG -- Continue to next step.

2. CHECK WIRE HARNESS (A/C ECU - BODY GROUND)




(a) Disconnect the A8 ECU connector.
(b) Measure the resistance and voltage of the wire harness side connector.
Standard resistance:






Standard voltage






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

3. CHECK RESISTANCE OF COMMUNICATION LINE




(a) Disconnect the A8 and G1 ECU connectors.
(b) Disconnect the 1G junction block connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:






Result:






C -- REPAIR OR REPLACE HARNESS AND CONNECTOR
B -- REPLACE A/C ECU AND REPAIR OR REPLACE HARNESS AND CONNECTOR
A -- REPLACE A/C ECU