Inspection Procedure

HINT:

• If other DTCs relating to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
• Read freeze frame data using an intelligent tester or OBD II scan tool. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

1. READ VALUE OF INTELLIGENT TESTER OR OBD II SCAN TOOL (INTAKE AIR TEMPERATURE) 
   1. Connect an intelligent tester or OBD II scan tool to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester or scan tool ON.
   4. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   5. Read the value displayed on the tester.
   6. If using an OBD II scan tool, refer to the instruction information.

      Standard: Same as actual Intake Air Temperature (IAT). 

      Result 

      RESULT
      
      

      Temperature Displayed	Proceed to
      -40°C (-40°F)	A
      140°C (284°F) or higher	B
      Same as actual IAT	C

      HINT:

      • If there is an open circuit, the intelligent tester or OBD II scan tool indicates -40°C (-40°F).
      • If there is a short circuit, the intelligent tester or OBD II scan tool indicates 140°C (284°F) or higher.

   B : Go to step   4 

   C : CHECK FOR INTERMITTENT PROBLEMS 

   A : Go to next step 

2. READ VALUE OF INTELLIGENT TESTER OR OBD II SCAN TOOL (CHECK FOR OPEN IN WIRE HARNESS) 
   1. Confirm good connection of Mass Air Flow (MAF) meter.
      Fig 1: Connecting Terminals THA And E2 Of MAF Meter Wire Harness Side Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Disconnect the M1 MAF meter connector.
   3. Connect terminals THA and E2 of the MAF meter wire harness side connector.
   4. Connect the intelligent tester or OBD II scan tool to the DLC3.
   5. Turn the ignition switch to ON.
   6. Turn the tester or scan tool ON.
   7. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   8. Read the value displayed on the tester.
   9. If using an OBD II scan tool, refer to the instruction information.

      Standard: 140°C (284°F) or higher 

   10. Reconnect the MAF meter connector.

   OK : REPLACE MASS AIR FLOW METER 

   NG : GO TO NEXT STEP 

3. READ VALUE OF INTELLIGENT TESTER OR OBD II SCAN TOOL (CHECK FOR OPEN IN ECM) 
   1. Confirm good connection of ECM.
      Fig 2: Checking Open In ECM

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Disconnect the M1 MAF meter connector.
   3. Connect terminals THA and E2 of the E3 ECM connector.

      HINT:

      Before checking, do visual and contact pressure checks on the ECM connector.

   4. Connect the intelligent tester or OBD II scan tool to the DLC3.
   5. Turn the ignition switch to ON.
   6. Turn the tester or scan tool ON.
   7. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   8. Read the value displayed on the tester.
   9. If using an OBD II scan tool, refer to the instruction information.

      Standard: 140°C (284°F) or higher 

   10. Reconnect the MAF meter connector.

   OK : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   NG : REPLACE ECM 

4. READ VALUE OF INTELLIGENT TESTER OR OBD II SCAN TOOL (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the M1 MAF meter connector.
      Fig 3: Checking Short In Wire Harness

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect the intelligent tester or OBD II scan tool to the DLC3.
   3. Turn the ignition switch to ON.
   4. Turn the tester or scan tool ON.
   5. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   6. Read the value displayed on the tester.
   7. If using an OBD II scan tool, refer to the instruction information.

      Standard: -40°C (-40°F) 

   8. Reconnect the MAF meter connector.

   OK : REPLACE MASS AIR FLOW METER 

   NG : GO TO NEXT STEP 

5. READ VALUE OF INTELLIGENT TESTER OR OBD II SCAN TOOL (CHECK FOR SHORT IN ECM) 
   1. Disconnect the E3 ECM connector.
      Fig 4: Checking Short In ECM

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect the intelligent tester or OBD II scan tool to the DLC3.
   3. Turn the ignition switch to ON.
   4. Turn the tester or scan tool ON.
   5. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   6. Read the value displayed on the tester.
   7. If using an OBD II scan tool, refer to the instruction information.

      Standard: -40°C (-40°F) 

   8. Reconnect the ECM connector.

   OK : REPAIR OR REPLACE HARNESS OR CONNECTOR 

   NG : REPLACE ECM