Inspection Procedure

HINT:

• If DTCs related 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 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. READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (INTAKE AIR TEMPERATURE) 
   1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
   2. Turn the ignition switch ON. Push the hand-held tester or the OBD II scan tool main switch ON.
   3. On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR. Read the values.

      Temperature: Same value as the actual intake air temperature. 

      Result: 

      TEMPERATURE SPECIFICATION
      
      

      Temperature Displayed	Proceed to
      -40°C (-40°F)	A
      140°C (284°F) or more	B
      OK (Same as present temperature)	C

   HINT:

   • If there is an open circuit, the hand-held tester or the OBD II scan tool indicates -40°C (-40°F).
   • If there is a short circuit, the hand-held tester or the OBD II scan tool indicates 140°C (284°F) or more.
   1. B : Go to step   4 
   2. C : CHECK FOR INTERMITTENT PROBLEMS (See  BASIC INSPECTION  ) 
   3. A : Go to Next Step. 
2. READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR OPEN IN WIRE HARNESS) 
   1. Disconnect the M1 MAF meter connector.
   2. Connect terminals THA and E2 of the M1 MAF meter wire harness side connector.
   3. Turn the ignition switch ON.
   4. On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR. Read the values.

      OK: Temperature value: 140°C (284°F) or more 

      Fig 1: Reading Value Of Hand-Held Tester Or OBD II Scan Tool (Checking For Open In Wire Harness)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK : CONFIRM GOOD CONNECTION AT SENSOR. IF OK, REPLACE MASS AIR FLOW METER 
   2. NG : Go to Next Step. 
3. READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR OPEN IN ECM) 
   1. Disconnect the M1 MAF meter connector.
   2. Connect terminals THA and E2 of the E8 ECM connector.

      HINT:

      Before checking, do a visual and contact pressure check for the ECM connector.

   3. Turn the ignition switch ON.
   4. On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR. Read the values.

      OK: Temperature value: 140°C (284°F) or more 

      Fig 2: Reading Value Of Hand-Held Tester Or OBD II Scan Tool (Checking For Open In ECM)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK : REPAIR OR REPLACE HARNESS AND CONNECTOR 
   2. NG : CONFIRM GOOD CONNECTION AT ECM. IF OK, REPLACE ECM (See  REPLACEMENT  ) 
4. READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the M1 MAF meter connector.
   2. Turn the ignition switch ON.
   3. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR" and read its value displayed on the hand-held tester or the OBD II scan tool.

      OK: Temperature value: -40°C (-40°F) 

      Fig 3: Reading Value Of Hand-Held Tester Or OBD II Scan Tool (Checking For Short In Wire Harness)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK : REPLACE MASS AIR FLOW METER 
   2. NG : Go to Next Step. 
5. READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR SHORT IN ECM) 
   1. Disconnect the E8 ECM connector.
   2. Turn the ignition switch ON.
   3. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR" and read its value displayed on the hand-held tester or the OBD II scan tool.

      OK: Temperature value: -40°C (-40°F) 

      Fig 4: Reading Value Of Hand-Held Tester Or OBD II Scan Tool (Check For Short In ECM)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. OK : REPAIR OR REPLACE HARNESS AND CONNECTOR 
   2. NG : REPLACE ECM (See  REPLACEMENT  )