Inspection Procedure

HINT:

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 (See FREEZE FRAME DATA ).

READ VALUE OF INTAKE AIR TEMPERATURE SENSOR (INTAKE AIR)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester on.
Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.

Read the value displayed on the tester.

Standard:

Same as actual Intake Air Temperature (IAT).

Result

RESULT REFERENCE

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

CHECK INTAKE AIR TEMPERATURE SENSOR (CHECK FOR OPEN IN SENSOR)
1. Confirm good connection of Mass Air Flow (MAF) meter.
2. Disconnect the E29 MAF meter connector.
3. Connect terminals THA and E2 of the MAF meter wire harness side connector.
4. Connect the intelligent tester to the DLC3.
5. Turn the engine switch on (IG).
6. Turn the tester on.
7. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
8. Read the value displayed on the tester.
  Standard:
  
  140°C (284°F) or higher
9. Reconnect the MAF meter connector.
OK: REPLACE MASS AIR FLOW METER

Fig 1: Identifying Intake Air Temperature Sensor (Check For Open In Sensor)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to next step
CHECK ECM (CHECK FOR OPEN IN ECM)

Fig 2: Identifying ECM (Check For Open In ECM)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Confirm good connection of the ECM.
2. Disconnect the E29 MAF meter connector.
3. Connect terminals THA and ETHA of the E5 ECM connector.
  HINT:
  
  Before checking, do visual and contact pressure checks on the ECM connector.
4. Connect the intelligent tester to the DLC3.
5. Turn the engine switch on (IG).
6. Turn the tester on.
7. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
8. Read the value displayed on the tester.
  Standard:
  
  140°C (284°F) or higher
9. Reconnect the MAF meter connector.
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR

NG: REPLACE ECM
CHECK INTAKE AIR TEMPERATURE SENSOR (CHECK FOR SHORT IN SENSOR)

Fig 3: Identifying Intake Air Temperature Sensor (Check For Short In Sensor)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Disconnect the E29 MAF meter connector.
2. Connect the intelligent tester to the DLC3.
3. Turn the engine switch on (IG).
4. Turn the tester on.
5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
6. Read the value displayed on the tester.
  Standard:
  
  -40°C (-40°F) or higher
7. Reconnect the MAF meter connector.
OK: REPLACE MASS AIR FLOW METER

NG: Go to next step
CHECK ECM (CHECK FOR SHORT IN ECM)

Fig 4: Identifying ECM (Check For Short In ECM)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. Disconnect the E5 ECM connector.
2. Connect the intelligent tester to the DLC3.
3. Turn the engine switch on (IG).
4. Turn the tester on.
5. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / INTAKE AIR.
6. Read the value displayed on the tester.
  Standard:
  
  -40°C (-40°F) or higher
7. Reconnect the ECM connector.
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR

NG: REPLACE ECM