Inspection Procedure

HINT:

Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. 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. READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE) 
   1. Connect an intelligent tester to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the tester ON.
   4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
   5. Read the value displayed on the tester.

      Standard: 

      Same as actual Intake Air Temperature (IAT). 

      Result 

      RESULT REFERENCE
      
      

      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 indicates -40°C (-40°F).
      • If there is a short circuit, the intelligent tester 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 USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS) 
   1. Disconnect the C26 Mass Air Flow (MAF) meter connector.
   2. Connect terminals THA and E2 of the MAF meter wire harness side connector.
   3. Connect the intelligent tester to the DLC3.
   4. Turn the ignition switch to ON.
   5. Turn the tester ON.
   6. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
   7. Read the value displayed on the tester.

      Standard: 

      140°C (284°F) or higher 

   8. Reconnect the MAF meter connector.

   OK: CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER 

   Fig 1: Identifying C26 Mass Air Flow Meter Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: GO TO NEXT STEP 

3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the C26 MAF meter connector.
   2. Disconnect the C20 ECM connector.
   3. Check the resistance.

      Standard resistance 

      RESISTANCE SPECIFICATION
      
      

      Tester Connections	Specified Conditions
      THA (C26-4) - THA (C20-65)	Below 1 Ω
      E2 (C26-5) - ETHA (C20-88)

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 2: Identifying C26 Mass Air Flow Meter & ECM Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM 

4. READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the C26 MAF meter connector.
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch to ON.
   4. Turn the tester ON.
   5. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
   6. Read the value displayed on the tester.

      Standard: 

      -40°C (-40°F) 

   7. Reconnect the MAF meter connector.

   OK: REPLACE MASS AIR FLOW METER 

   Fig 3: Identifying ECM Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: GO TO NEXT STEP 

5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the C26 MAF meter connector.
   2. Disconnect the C20 ECM connector.
   3. Check the resistance.

      Standard resistance 

      RESISTANCE SPECIFICATION
      
      

      Tester Connections	Specified Conditions
      THA (C26-4) or THA (C20-65) - Body ground	10 kΩ or higher

   4. Reconnect the MAF meter connector.
   5. Reconnect the ECM connector.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 4: Identifying C26 Mass Air Flow Meter & ECM Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE ECM