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 B1280, repair the "+B or GND short malfunction of communication bus" DTCs first.

1. INSPECT FUSE (MPX-B) 
   1. Remove the MPX-B 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 (MAIN BODY ECU LH - BATTERY AND BODY GROUND) 
   1. Disconnect the LD 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
   MPX-B (LD-18) - Body ground	Always	10 to 14 V

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION REFERENCE CHART
   
   

   Tester Connection	Specified Condition
   GND (LD-3) - Body ground	Below 1 Ω

   Fig 1: Identifying LD ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: Go to next step 

3. CHECK RESISTANCE OF COMMUNICATION LINE 
   1. Disconnect the Q3, A30, M7 and 2F ECU connectors.
   2. Measure the resistance between the specified terminals on the wire harness side connectors.

   Standard resistance 

Result 

Fig 2: Identifying Q3, A30, M7 And 2F ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

B: REPAIR OR REPLACE HARNESS OR CONNECTOR AND REPLACE MAIN BODY ECU LH 

C: REPAIR OR REPLACE HARNESS OR CONNECTOR 

A: REPLACE MAIN BODY ECU LH