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 to the ON position.
   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 

      DTC RESULT DESCRIPTION
      
      

      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 M6 Mass Air Flow (MAF) meter connector.
   2. Connect terminals THA and E2 of the MAF meter wire harness side connector.
      Fig 1: Connecting Terminals THA And E2 Of MAF Meter Wire Harness Side 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. 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: REPLACE MASS AIR FLOW METER  (See REMOVAL )

   NG: Go to next step 

3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the M6 MAF meter connector.
   2. Disconnect the E9 ECM connector.
      Fig 2: Identifying MAF Meter Connector And ECM Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Measure the resistance according to the value (s) in the table below.

      Standard resistance: 

      Check for open 

      STANDARD RESISTANCE SPECIFICATIONS
      
      

      Tester Connection	Specified Condition
      THA (E9-22) - THA (M6-1)	Below 1 Ω
      E2 (E9-28) - E2 (M6-2)	Below 1 Ω

      Check for short 

      DIAGNOSTIC PROCEDURE
      
      

      Tester Connection	Specified Condition
      THA (E9-22) or THA (M6-1) - Body ground	10 kΩ or higher
      E2 (E9-28) or E2 (M6-2) - Body ground	10 kΩ or higher

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

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER ECM) 

   NG: REPLACE ECM  (See REMOVAL )

4. READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS) 
   Fig 3: Checking Short In Wire Harness

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the M6 MAF meter connector.
   2. Connect the intelligent tester to the DLC3.
   3. Turn the ignition switch to the ON position.
   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 

   NG: Go to next step 

5. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
   1. Disconnect the M6 MAF meter connector.
   2. Disconnect the E9 ECM connector.
      Fig 4: Identifying MAF Meter Connector And ECM Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATIONS
      
      

      Tester Connection	Specified Condition
      THA (E9-22) or THA (M6-1) - Body ground	10 kΩ or higher

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

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER ECM) 

   NG: REPLACE ECM  (See REMOVAL )