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. 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 DATA LIST (INTAKE AIR TEMPERATURE) 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch to ON and turn the intelligent tester ON.
   3. Select the following menu Items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
   4. Read the values displayed on the tester.

      Standard: 

      Same value as actual IAT. 

      Result 

      RESULT REFERENCE CHART
      
      

      Temperature Displayed	Proceed to
      -40°C (-40°F)	A
      140°C (284°F)	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).

   B:  Go to step  4

   C : CHECK FOR INTERMITTENT PROBLEMS 

   A: Go to Next Step 

2. READ DATA LIST (CHECK FOR OPEN IN WIRE HARNESS) 
   1. Disconnect the M1 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 and turn the intelligent 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: 

      140°C (284°F) 

   7. Reconnect the MAF meter connector.
   Fig 1: Identifying MAF Meter Connector Terminals
   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

   NG: Go to Next Step 

3. READ DATA LIST (CHECK FOR OPEN IN ECM) 
   1. Disconnect the M1 MAF meter connector.
   2. Connect terminals THA and E2 of the ECM connector.

      HINT:

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

   3. Connect the intelligent tester to the DLC3.
   4. Turn the ignition switch to ON and turn the intelligent 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: 

      140°C (284°F) 

   7. Reconnect the MAF meter connector.
   Fig 2: Connecting Terminals THA And E2 Of ECM Connector
   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

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

   OK : REPAIR OR REPLACE HARNESS OR CONNECTOR 

4. READ DATA LIST (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the M1 MAF meter connector.
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch to ON and turn the intelligent 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: 

      -40°C (-40°F) 

   6. Reconnect the MAF meter connector.
      Fig 3: Disconnecting M1 MAF Meter Connector

      Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

   OK : REPLACE MASS AIR FLOW METER 

   NG: Go to Next Step 

5. READ DATA LIST (CHECK FOR SHORT IN ECM) 
   1. Disconnect the E4 and E5 ECM connector.
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch to ON and turn the intelligent 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: 

      -40°C (-40°F) 

   6. Reconnect the ECM connectors.
   Fig 4: Disconnecting E4 And E5 ECM Connector
   Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.

   NG: REPLACE ECM 

   OK : REPAIR OR REPLACE HARNESS OR CONNECTOR