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.
   2. Turn the ignition switch on (IG).
   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 CHART
   
   

   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 OF INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS) 
   1. Disconnect the 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 on (IG).
   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.
   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 VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN ECM) 
   1. Disconnect the MAF meter connector.
   2. Connect terminals THA and E2 of the ECM connector.

      HINT:

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

   3. Connect the intelligent tester to the DLC3.
   4. Turn the ignition switch on (IG).
   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 

      Fig 2: Reading Value Of Intelligent Tester (Check For Open In ECM)

      Courtesy of TOYOTA MOTOR SALES, U.S.A., INC.
   8. Reconnect the MAF meter connector.

   OK: REPAIR or REPLACE HARNESS or CONNECTOR 

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

4. READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the MAF meter connector.
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch on (IG).
   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.
   Fig 3: Reading Value Of Intelligent Tester (Check For Short In Wire Harness)

   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 

5. READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN ECM) 
   1. Disconnect the ECM connector.
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch on (IG).
   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 ECM connector.
   Fig 4: Reading Value Of Intelligent Tester (Check For Short In ECM)

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

   OK: REPAIR or REPLACE HARNESS or CONNECTOR 

   NG: REPLACE ECM