Inspection Procedure

WARNING: This page is about a different variant/trim than selected.

HINT:

If DTCs that are related to different systems are output simultaneously while terminal E2 is used as a ground terminal, terminal E2 may have an open circuit.
Read freeze frame data using the hand-held tester or the OBDII scan tool. 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.

READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (INTAKE AIR TEMPERATURE)

Connect the hand-held tester or the OBD II scan tool to the DLC3.
Turn ON the ignition switch. Push the hand-held tester or the OBD II scan tool main switch ON.

On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR. Read the values.

Temperature: The same as actual intake air temperature.

Result:

IAT DISPLAY

Display	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 hand-held tester or the OBD II scan tool indicates -40°C (-40°F).
If there is a short circuit, the hand-held tester or the OBD II scan tool indicates 140°C (284°F) or more.

B: Go to step 4
C: CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )
A: GO TO NEXT STEP.

READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR OPEN IN HARNESS)
1. Disconnect the M1 MAF meter connector.
2. Connect terminals THA and E2 of the M1 MAF meter wire harness side connector.
3. Turn the ignition switch ON.
4. On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR. Read the values.
  
  Fig 1: Connecting MAF Harness Connector Terminals THA And E2
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: Temperature value: 140°C (284°F) or more
1. OK: REPLACE MASS AIR FLOW METER (IAT SENSOR)
2. NG: GO TO NEXT STEP.
READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR OPEN IN ECM)
1. Disconnect the M1 MAF meter connector.
2. Connect terminals THA and E2 of the E7 ECM connector.
  HINT:
  
  Before checking, do a visual and contact pressure check for the ECM connector.
3. Turn the ignition switch ON.
4. On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR. Read the values.
  
  Fig 2: Connecting E7 ECM Connector Terminals THA And E2
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: Temperature value: 140°C (284°F) or more
1. OK: REPAIR OR REPLACE HARNESS OR CONNECTOR
2. NG: CONFIRM GOOD CONNECTION AT ECM. IF OK, REPLACE ECM (See REPLACEMENT )
READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR SHORT IN HARNESS)
1. Disconnect the M1 MAF meter connector.
2. Turn the ignition switch ON.
3. On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR. Read the values.
  
  Fig 3: Disconnecting MAF Meter Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: Temperature value: -40°C (-40°F)
1. OK: REPLACE MASS AIR FLOW METER
2. NG: GO TO NEXT STEP.
READ VALUE OF HAND-HELD TESTER OR OBD II SCAN TOOL (CHECK FOR SHORT IN ECM)
1. Disconnect the E7 ECM connector.
2. Turn the ignition switch ON.
3. On the hand-held tester or the OBD II scan tool, enter the following menus: DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR. Read the values.
  
  Fig 4: Disconnecting ECM Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: Temperature value: -40°C (-40°F)
1. OK: REPAIR OR REPLACE HARNESS OR CONNECTOR
2. NG: REPLACE ECM (See REPLACEMENT )