B1262 Air conditioning amplifier (A/C ECU) communication stops

DESCRIPTION

1. This DTC is detected when communication between the air conditioning amplifier (A/C ECU) and multiplex network gateway ECU stops for more than 10 seconds.
   

DTC No.	DTC Detection Condition	Trouble Area
B1262	Air conditioning amplifier (A/C ECU) communication stops	Air conditioning amplifier (A/C ECU) Wire harness

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

When "+B of GND short malfunction of communication bus" DTCs (B1266 and B1267) are detected at the same time as "communication stop" DTC B1262, repair the "+B or GND short malfunction of communication bus" DTCs first.

1. CHECK FUSE (ECU-IG No.1)

1. Remove the ECU-IG No.1 fuse from the fusible link block.

2. Measure the resistance of the fuse.

   Standard resistance:

   Below 1 Ω
   

NG	REPLACE FUSE

OK

2. CHECK WIRE HARNESS (AIR CONDITIONING AMPLIFIER ASSEMBLY - BATTERY AND BODY GROUND)

1. Disconnect the A11 ECU connector.

2. Measure the voltage of the wire harness side connector.

   Standard voltage:

   Tester Connection	Condition	Specified Condition
   A11-1 (IG+) - Body ground	Ignition switch ON	10 to 14 V

3. Measure the resistance of the wire harness side connector.

   Standard resistance:

   Tester Connection	Condition	Specified Condition
   A11-6 (GND) - Body ground	Always	Below 1 Ω

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3. CHECK RESISTANCE OF COMMUNICATION LINE

1. Disconnect the G1 and A24 ECU connectors.
   

2. Measure the resistance of the wire harness side connectors.

Standard resistance:

Tester Connection	Specified Condition
A11-4 (MPX-) - G1-4 (MPI1)	Below 1 Ω
A11-3 (MPX+) - A24-22 (MPX2)	Below 1 Ω

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK
REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY