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 B1271, repair the "+B or GND short malfunction of communication bus" DTCs first.

1. INSPECT FUSE (DOME, MPX-B) 
   1. Remove the DOME and MPX-B fuses from the engine room J/B No. 1.
   2. Measure the resistance of the fuse.

      Standard resistance: 

      Below 1 Ω 

      NG: REPLACE FUSE 

      OK: Go to next step 

2. CHECK WIRE HARNESS (COMBINATION METER ECU - BATTERY AND BODY GROUND) 
   1. Disconnect the J34 ECU connector.
   2. Measure the voltage and resistance of the wire harness side connector.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART
   
   

   Tester Connection	Condition	Specified Condition
   B (J34-23) - Body ground	Always	10 to 14 V
   B (J34-24) - Body ground	Always	10 to 14 V

   Fig 1: Identifying J34 ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART
   
   

   Tester Connection	Specified Condition
   E2 (J34-1) - Body ground	Below 1 Ω
   ES (J34-13) - Body ground	Below 1 Ω

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: Go to next step 

3. CHECK RESISTANCE OF COMMUNICATION LINE 
   1. Disconnect the J34, J49, J76, A27 and J58 ECU connectors.
   2. Measure the resistance between the specified terminals on the wire harness side connectors.

   Standard resistance 

Result 

Fig 2: Identifying J34, J49, J76, A27 And J58 ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

B: REPLACE COMBINATION METER ECU AND REPAIR OR REPLACE HARNESS OR CONNECTOR 

C: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE COMBINATION METER ECU