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 B1278, repair the "+B or GND short malfunction of communication bus" DTCs first.

1. INSPECT FUSE (ECU-IG RH, MPX-B) 
   1. Remove the ECU-IG RH fuse from the cowl side J/B RH.
   2. Remove the MPX-B fuse from the engine room J/B No. 1.

      Standard resistance: 

      Below 1 Ω 

      NG: REPLACE FUSE 

      OK: Go to next step 

2. CHECK WIRE HARNESS (COMBINATION SWITCH ASSEMBLY - BATTERY AND BODY GROUND) 
   1. Disconnect the J26 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 (J26-1) - Body ground	Always	10 to 14 V
   IG (J26-2) - Body ground	Engine switch on (IG)	10 to 14 V

   Fig 1: Identifying J26 ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART
   
   

   Tester Connection	Specified Condition
   E (J26-5) - 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 J26, J76 and J55 ECU connectors.
   2. Measure the resistance between the specified terminals on the wire harness side connectors.

   Standard resistance 

Result 

Fig 2: Identifying J26, J76 And J55 ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

B: REPAIR OR REPLACE HARNESS OR CONNECTOR AND REPLACE COMBINATION SWITCH ASSEMBLY 

C: REPAIR OR REPLACE HARNESS OR CONNECTOR 

A: REPLACE COMBINATION SWITCH ASSEMBLY