Inspection Procedure

HINT

If "+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 (See DTC B1266 SHORT TO B+ IN INSTRUMENT PANEL SYSTEM COMMUNICATION BUS MALFUNCTION; DTC B1267 SHORT TO GND IN INSTRUMENT PANEL SYSTEM COMMUNICATION BUS MALFUNCTION  )

1. CHECK FUSE (A/C) 
   1. Remove the A/C fuse from the main body ECU LH (cowl side junction block LH)
   2. Measure the resistance according to the value(s) in the table below

      Standard Resistance 

      RESISTANCE REFERENCE
      
      

      Tester Connection	Condition	Specified Condition
      A/C fuse	Always	Below 1 Ω

   NG: REPLACE FUSE (A/C) 

   OK: Go to Next Step 

2. CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY AND BODY GROUND) 
   1. Disconnect the J58 connector.
   2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard Voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      J58-1 (B) - Body ground	Always	11 to 14 V

      Standard Resistance 

      RESISTANCE REFERENCE
      
      

      Tester Connection	Condition	Specified Condition
      J58-20 (GND) - Body ground	Always	Below 1 Ω

   Fig 1: Identifying J58 Connector Terminal
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (A/C AMPLIFIER - BATTERY AND BODY GROUND) 

   OK: Go to Next Step 

3. CHECK HARNESS AND CONNECTOR (COMMUNICATION LINE) 
   1. Disconnect the J58, A27 and J76 connectors.
   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      RESISTANCE REFERENCE
      
      

      Tester Connection	Condition	Specified Condition
      J58-31 (MPX-) - A27-5 (MPX1)	Always	Below 1 Ω
      J58-30 (MPX+) - J76-13 (MPI2)	Always	Below 1 Ω

   Fig 2: Identifying J58, A27 And J76 Connector Terminal
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE A/C AMPLIFIER ASSEMBLY  (See REMOVAL )