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 the intelligent tester. 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 (INTAKE AIR TEMPERATURE) 
   1. Connect the intelligent tester to the DLC3 with CAN VIM.
   2. Turn the ignition switch ON and turn the intelligent tester ON.
   3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   4. Read the values.

      Standard: 

      Same value as actual Intake Air Temperature (IAT). 

      Result 

      RESULT REFERENCE
      
      

      Intake Air Temperature	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 intelligent tester indicates -40°C (-40°F).
      • If there is a short circuit, the intelligent tester indicates 140°C (284°F) or more.

   B:  Go to step  4

   C: CHECK FOR INTERMITTENT PROBLEMS 

   A: Go to next step 

2. READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS) 
   Fig 1: Identifying M1 Mass Air Flow (MAF) Meter Connector Terminals
   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
   1. Disconnect the M1 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 with CAN VIM.
   4. Turn the ignition switch ON and turn the intelligent tester ON.
   5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   6. Read the value.

      Standard: 

      140°C (284°F) or more 

   7. Reconnect the MAF meter connector.

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

   NG: Go to next step 

3. READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN ECM) 
   Fig 2: Identifying M1 MAF Meter Connector Terminal

   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
   1. Disconnect the M1 MAF meter connector.
   2. Connect terminals THA and E2 of the E5 ECM connector.

      HINT:

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

   3. Connect the intelligent tester to the DLC3 with CAN VIM.
   4. Turn the ignition switch ON and turn the intelligent tester ON.
   5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   6. Read the value.

      Standard: 

      140°C (284°F) or more 

   7. Reconnect the MAF meter connector.

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

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR 

4. READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) 
   Fig 3: Identifying M1 MAF Meter Connector Terminal

   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
   1. Disconnect the M1 MAF meter connector.
   2. Connect the intelligent tester to the DLC3 with CAN VIM.
   3. Turn the ignition switch ON and turn the intelligent tester ON.
   4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   5. Read the value.

      Standard: 

      -40°C (-40°F) 

   6. Reconnect the MAF meter connector.

   OK: REPLACE MASS AIR FLOW METER 

   NG: Go to next step 

5. READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN ECM) 
   Fig 4: Identifying MAF Sensor Connector Terminal

   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
   1. Disconnect the M1 MAF meter connector.
   2. Disconnect the E5 ECM connector.
   3. Connect the intelligent tester to the DLC3 with CAN VIM.
   4. Turn the ignition switch ON and turn the intelligent tester ON.
   5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   6. Read the value.

      Standard: 

      -40°C (-40°F) 

   7. Reconnect the ECM connector.
   8. Reconnect the MAF meter connector.

   NG: REPLACE ECM 

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR