Inspection Procedure

HINT:

Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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. INSPECT HEATED OXYGEN SENSOR (HEATER RESISTANCE) 
   1. Disconnect the H10 heated oxygen sensor connector.
   2. Measure the resistance of the heated oxygen sensor terminals.
      Fig 1: Identifying Heated Oxygen Sensor Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      TESTER CONNECTION AND CONDITION SPECIFICATIONS
      
      

      Tester Connection	Condition	Specified Condition
      H10-2 (HT) - H10-1 (+B)	20°C (68°F)	11 to 16 kΩ
      H10-2 (HT) - H10-1 (+B)	800°C (1,472°F)	23 to 32 kΩ

   1. NG: REPLACE HEATED OXYGEN SENSOR 
   2. OK: Go to next Step. 
2. INSPECT RELAY (EFI) 
   1. Remove the EFI relay from the engine room J/B.
   2. Measure the resistance of the EFI relay.
      Fig 2: Identifyiing EFI Relay Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      TESTER CONNECTION AND CONDITION SPECIFICATIONS
      
      

      Tester Connection	Specified Condition
      3 - 5	10 kΩ or higher
      3 - 5	Below 1 Ω (when battery voltage is applied to terminals 1 and 2)

   1. NG: REPLACE RELAY 
   2. OK: GO TO NEXT STEP. 
3. INSPECT ECM (HT1B VOLTAGE) 
   1. Turn the ignition switch ON.
   2. Measure the voltage of the ECM connectors.
      Fig 3: Identifying ECM E8 E9 Connector Terminals

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard: 

      TESTER CONNECTION AND CONDITION SPECIFICATIONS
      
      

      Tester Connection	Specified Condition
      E8-21 (HT1B) - E9-1 (E1)	9 to 14 V

   1. OK: REPLACE ECM (See REPLACEMENT )
   2. NG: GO TO NEXT STEP. 
4. CHECK WIRE HARNESS (ECM - HEATED OXYGEN SENSOR, HEATED OXYGEN SENSOR - EFI RELAY) 
   1. Check the wire harness between the ECM and heated oxygen sensor.
      1. Disconnect the E8 ECM connector.
      2. Disconnect the H10 heated oxygen sensor connector.
      3. Measure the resistance of the wire harness side connectors.
         Fig 4: Identifying E8 ECM & Heated Oxygen Sensor Connector Terminals

         Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

         Standard: 

         TESTER CONNECTION AND CONDITION SPECIFICATIONS
         
         

         Tester Connection	Specified Condition
         H10-2 (HT)- E8-21 (HT1B)	Below 1 Ω
         H10-2 (HT) or E8-21 (HT1B) - Body ground	10 kΩ or higher

   2. Check the wire harness between the heated oxygen sensor and EFI relay.
      1. Disconnect the H10 heated oxygen sensor connector.
      2. Remove the EFI relay from the engine room J/B.
      3. Measure the resistance of the wire harness side connectors.
         Fig 5: Identifying Heated Oxygen Sensor Connector Terminals & EFI Engine Relay Location

         Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

         Standard: 

         TESTER CONNECTION AND CONDITION SPECIFICATIONS
         
         

         Tester Connection	Specified Condition
         H10-1 (+B) - J/B EFI relay terminal 3	Below 1 Ω
         H10-1 (+B) or J/B EFI relay terminal 3 - Body ground	10 kΩ or higher

   1. NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 
   2. OK: REPLACE ECM (See  REPLACEMENT  )