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 OUTPUT DTC 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch to the ON position and turn the tester on.
   3. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.
   4. Read the DTCs.

      Result 

      DTC OUTPUT RESULT
      
      

      Display (DTC Output)	Proceed to
      P0110	A
      P0112	B
      P0113	C

   B:  Go to step  5

   C:  Go to step  4

   A: Go to next step 

2. READ VALUE USING INTELLIGENT TESTER (INTAKE AIR TEMPERATURE) 
   1. Connect the intelligent tester to the DLC3.
   2. Turn the ignition switch to the ON position.
   3. Turn the tester on.
   4. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   5. Read the value displayed on the tester.

      Standard: 

      Same as the actual Intake Air Temperature (IAT). 

      Result 

      DTC OUTPUT RESULT
      
      

      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  5

   C: CHECK FOR INTERMITTENT PROBLEMS 

   A: Go to next step 

3. READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS) 
   1. Disconnect the M1 MAF meter connector.
   Fig 1: MAF Meter - Circuit Diagram
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect terminal THA of the MAF meter wire harness side connector.
   3. Connect the intelligent tester to the DLC3.
   4. Turn the ignition switch to the ON position 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 temperature: 

      140°C (284°F) or more 

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

   NG: Go to next step 

4. READ VALUE USING INTELLIGENT TESTER (CHECK FOR OPEN IN ECM) 
   1. Disconnect the M1 MAF meter connector.
      Fig 2: MAF Meter Connector - Circuit Diagram

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect terminals THA and E2 of the E7 and E8 ECM connectors.

      HINT:

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

      Fig 3: Identifying THA And E2 Terminals Of E8 And E7 ECM Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Connect the intelligent tester to the DLC3.
   4. Turn the ignition switch to the ON position.
   5. Turn the tester on.
   6. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   7. Read the value displayed on the tester.

      Standard temperature: 

      140°C (284°F) or higher 

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

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR 

5. READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) 
   1. Disconnect the M1 MAF meter connector.
   Fig 4: MAF Meter - Circuit Diagram
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch to the ON position.
   4. Turn the tester on.
   5. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / INTAKE AIR.
   6. Read the value displayed on the tester.

      Standard temperature: 

      -40°C (-40°F) 

   OK: REPLACE MASS AIR FLOW METER 

   NG: Go to next step 

6. READ VALUE USING INTELLIGENT TESTER (CHECK FOR SHORT IN ECM) 
   1. Disconnect the E7 and E8 ECM connectors.
      Fig 5: MAF Meter Connector - Circuit Diagram

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch to the ON position.
   4. Turn the tester on.
   5. Enter the following menus: DIAGNOSIS / ENHANCED OBD 117 DATA LIST / ALL / INTAKE AIR.
   6. Read the value displayed on the tester.

      Standard temperature: 

      -40°C (-40°F) 

   NG: REPLACE ECM  (See REMOVAL  )

   Fig 6: Identifying E8 And E7 ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR