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 Techstream. 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.

READ VALUE OF TECHSTREAM (INTAKE AIR TEMPERATURE)

Connect Techstream to the DLC3.
Turn the ignition switch to the ON position.
Turn the tester on.
On the tester, select the following menu items: Powertrain / Engine and ECT / Data List / Intake Air.

Read the value displayed on the tester.

Standard: Same as actual Intake Air Temperature (IAT).

Result

DTC RESULT DESCRIPTION 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, Techstream indicates -40°C (-40°F).

If there is a short circuit, Techstream indicates 140°C (284°F) or higher.

B: Go to step 4

C: CHECK FOR INTERMITTENT PROBLEMS

A: Go to Next Step

READ VALUE OF TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)
1. Confirm connector connecting condition.
2. Disconnect the M1 Mass Air Flow (MAF) meter connector.
3. Connect terminals THA and E2 of the MAF meter wire harness side connector.
4. Connect Techstream to the DLC3.
5. Turn the ignition switch to the ON position.
6. Turn the tester on.
7. On the tester, select the following menu items: Powertrain / Engine and ECT / Data List / 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

NG: Go to Next Step
READ VALUE OF TECHSTREAM (CHECK FOR OPEN IN ECM)
1. Confirm connector connecting condition.
2. Disconnect the M1 MAF meter connector.
3. Connect terminals THA and E2 of the E3 ECM connector.
  HINT:
  
  Before checking, do visual and contact pressure checks on the ECM connector.
  
  Fig 2: Identifying Terminals THA And E2 Of E3 ECM Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Connect Techstream to the DLC3.
5. Turn the ignition switch to the ON position.
6. Turn the tester on.
7. On the tester, select the following menu items: Powertrain / Engine and ECT / Data List / 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
READ VALUE OF TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the M1 MAF meter connector.
2. Connect Techstream 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: Powertrain / Engine and ECT / Data List / Intake Air.
6. Read the value displayed on the tester.
  Standard: -40°C (-40°F)
7. Reconnect the MAF meter connector.
  
  Fig 3: Identifying MAF Meter Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK: REPLACE MASS AIR FLOW METER

NG: Go to Next Step
READ VALUE OF TECHSTREAM (CHECK FOR SHORT IN ECM)
1. Disconnect the E3 ECM connector.
2. Connect Techstream 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: Powertrain / Engine and ECT / Data List / Intake Air.
6. Read the value displayed on the tester.
  Standard: -40°C (-40°F)
7. Reconnect the ECM connector.
  
  Fig 4: Identifying MAF And ECM Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK: REPAIR OR REPLACE HARNESS OR CONNECTOR

NG: REPLACE ECM