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 air conditioning amplifier (A/C ECU) and gateway ECU stops for more than 10 seconds.





WIRING DIAGRAM





INSPECTION PROCEDURE
HINT:
When "+B of GND short malfunction of communication bus" DTCs (B1214 and B1215) are detected at the same time as "communication stop" DTC B1262, repair the "+B or GND short malfunction of communication bus" DTCs first.

PROCEDURE

1. CHECK FUSE (A/C)
(a) Remove the A/C fuse from the cowl side J/B LH.
(b) Measure the resistance of the fuse.
Standard resistance:
Below 1 Ohms
NG -- REPLACE FUSE
OK -- Continue to next step.
2. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER - BATTERY AND BODY GROUND)




(a) Disconnect the J58 ECU connector.
(b) Measure the voltage and resistance of the wire harness side connector.
Standard voltage:






Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK RESISTANCE OF COMMUNICATION LINE




(a) Disconnect the J58, A27, J34 and J76 ECU connectors.
(b) Measure the resistance of the wire harness side connector.
Standard resistance:





*1: w/ Adaptive front-lighting system
*2: w/o Adaptive front-lighting system
Result:






C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
B -- REPLACE AIR CONDITIONING AMPLIFIER AND REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY