Inspection Procedure

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

HINT:

Read freeze frame data using the 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 help determine if the vehicle was moving or stationary, 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 USING TECHSTREAM (INTAKE AIR TEMPERATURE)

Connect the Techstream to the DLC3.
Turn the ignition switch to ON.
Turn the Techstream on.
Enter the following menus: Powertrain/Engine/Data List/All Data/Intake Air.

Read the value displayed on the Techstream.

OK:

Same as actual intake air temperature.

Result

RESULT CHART

Result	Proceed to
-40°C (-40°F)	A
140°C (284°F) or higher	B
Same as actual intake air temperature	C

HINT:

If there is an open circuit, the Techstream indicates 40°C (-40°F).
If there is a short circuit, the Techstream indicates 140°C (284°F) or higher.
B: Go to step 4

C: CHECK FOR INTERMITTENT PROBLEMS (See CHECK FOR INTERMITTENT PROBLEMS )

A: Go to next step

READ VALUE USING TECHSTREAM (CHECK FOR OPEN IN WIRE HARNESS)
1. Disconnect the mass air flow meter connector.
2. Connect terminals 1 (THA) and 2 (E2) of the mass air flow meter wire harness side connector.
3. Connect the Techstream to the DLC3.
4. Turn the ignition switch to ON.
5. Turn the Techstream on.
6. Enter the following menus: Powertrain/Engine/Data List/All Data/Intake Air.
7. Read the value displayed on the Techstream.
  Standard value:
  
  140°C (284°F) or higher
8. Reconnect the mass air flow meter connector.
  NG: Go to step 3
  
  Fig 1: Identifying Mass Air Flow Meter Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: REPLACE MASS AIR FLOW METER (See REMOVAL )

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

Disconnect the mass air flow meter connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Open)

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
B10-1 (THA) - B50-6 (THA)	Always	Below 1 Ω
B10-2 (E2) - B50-12 (ETHA)	Always	Below 1 Ω

Reconnect the mass air flow meter connector.
Reconnect the ECM connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 2: Identifying Mass Air Flow Meter And ECM Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPLACE ECM (See REMOVAL )

READ VALUE USING TECHSTREAM (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the mass air flow meter connector.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Powertrain/Engine/Data List/All Data/Intake Air.
6. Read the value displayed on the Techstream.
  Standard value:
  
  -40°C (-40°F)
7. Reconnect the mass air flow meter connector.
  NG: Go to step 5
  
  Fig 3: Mass Air Flow Meter Circuit Diagram
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  OK: REPLACE MASS AIR FLOW METER (See REMOVAL )

CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM)

Disconnect the mass air flow meter connector.
Disconnect the ECM connector.

Measure the resistance according to the value(s) in the table below.

Standard Resistance (Check for Short)

TESTER CONNECTION SPECIFIED CONDITION CHART

Tester Connection	Condition	Specified Condition
B10-1 (THA) or B50-6 (THA) - Body ground	Always	10 kΩ or higher

Reconnect the mass air flow meter connector.
Reconnect the ECM connector.
NG: REPAIR OR REPLACE HARNESS OR CONNECTOR

Fig 4: Identifying Mass Air Flow Meter And ECM Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: REPLACE ECM (See REMOVAL )