Inspection Procedure

HINT:

Operating the engine switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

1. DISCONNECT CABLE FROM NEGATIVE BATTERY TERMINAL 
   1. Disconnect the cable from the negative (-) battery terminal before measuring the resistances of the main wire and the branch wire.
      CAUTION: Wait at least 90 seconds after disconnecting the cable from the negative (-) battery terminal to disable the SRS system.
      NOTE:

      • w/ Navigation System:

        After the engine switch is turned off, the HDD navigation system requires approximately 6 minutes to record various types of memory and settings. As a result, after turning the engine switch off, wait 6 minutes or more before disconnecting the cable from the negative (-) battery terminal.

      • When disconnecting the cable, some systems need to be initialized after the cable is reconnected (See INITIALIZATION ).
2. CHECK FOR OPEN IN CAN BUS WIRE (NETWORK GATEWAY ECU BRANCH WIRE) 
   1. Disconnect the E31 network gateway ECU connector.
   2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Switch Condition	Specified Condition
   E31-16 (CA1H) - E31-15 (CA1L)	Engine switch off	54 to 69 Ω

   Fig 1: Identifying E31 Network Gateway ECU Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE NETWORK GATEWAY ECU BRANCH WIRE OR CONNECTOR (CA1H, CA1L) 

   OK: Go to next step 

3. CHECK HARNESS AND CONNECTOR (NETWORK GATEWAY ECU - BATTERY AND BODY GROUND) 
   1. Connect the cable to the negative (-) battery terminal.
      NOTE: When disconnecting the cable, some systems need to be initialized after the cable is reconnected (See INITIALIZATION ).
   2. Disconnect the E31 network gateway ECU connector.
   3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      E31-4 (GND) - Body ground	Always	Below 1 Ω

   4. Measure the voltage according to the value(s) in the table below.
   Fig 2: Identifying E31 Network Gateway ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Switch Condition	Specified Condition
   E31-2 (BATT) - Body ground	Always	11 to 14 V
   E31-10 (IG1) - Body ground	Engine switch on (IG)	11 to 14 V
   E31-9 (IG2) - Body ground

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE NETWORK GATEWAY ECU  (See REMOVAL )