Inspection Procedure

HINT:

Read freeze frame data using Techstream. The ECM (Included in HV control ECU) records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.

1. CHECK FUSE (ETCS FUSE) 
   1. Remove the ETCS fuse from the engine R/B No. 4.
   2. Check the ETCS fuse resistance.

      Standard resistance: Below 1 Ω 

   3. Reinstall the ETCS fuse.
   Fig 1: Identifying ETCS Fuse
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED TO FUSE 

   OK: Go to Next Step 

2. INSPECT HV CONTROL ECU (+BM VOLTAGE) 
   1. Measure the voltage between the terminals of the H31 and H34 HV control ECU connectors.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      +BM (H34-3) - ME01 (H31-4)	9 to 14 V

   Fig 2: Identifying Terminals Of H31 And H34 HV Control ECU Connectors
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: CHECK FOR INTERMITTENT PROBLEMS 

   NG: Go to Next Step 

3. CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - ETCS FUSE, ETCS FUSE - BATTERY) 
   1. Check the harness and connector between the ETCS fuse and HV control ECU.
      1. Remove the ETCS fuse from the engine R/B No. 4.
      2. Disconnect the H34 HV control ECU connector.
      3. Measure the resistance according to the value (s) in the table below.

         Standard resistance (Check for open) 

         TESTER CONNECTION SPECIFIED CONDITION CHART
         
         

         Tester Connection	Specified Condition
         ETCS fuse (2) - +BM (H34-3)	Below 1 Ω

         Standard resistance (Check for short) 

         TESTER CONNECTION SPECIFIED CONDITION CHART
         
         

         Tester Connection	Specified Condition
         ETCS fuse (2) or +BM (H34-3) - Body ground	10 kΩ or higher

      4. Reinstall the ETCS fuse.
      5. Reconnect the HV control ECU connector.
   2. Check the harness and connector between the ETCS fuse and positive battery cable.
      1. Remove the ETCS fuse from the engine R/B No. 4.
      2. Disconnect the positive battery cable.
      3. Measure the resistance according to the value (s) in the table below.

         Standard resistance (Check for open) 

         TESTER CONNECTION SPECIFIED CONDITION CHART
         
         

         Tester Connection	Specified Condition
         Positive battery cable - ETCS fuse (1)	Below 1 Ω

         Fig 3: Identifying Terminals Of H34 HV Control ECU Connector

         Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

         Standard resistance (Check for short) 

         TESTER CONNECTION SPECIFIED CONDITION CHART
         
         

         Tester Connection	Specified Condition
         Positive battery cable or ETCS fuse (1) - Body ground	10 kΩ or higher

      4. Reinstall the ETCS fuse.
      5. Reconnect the positive battery cable.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE HV CONTROL ECU