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 an intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. 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 OF INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)

Connect an intelligent tester to the DLC3.
Turn the ignition switch ON.
Turn the tester ON.
Select the following menu items: 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

READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN WIRE HARNESS)
1. Disconnect the M1 Mass Air Flow (MAF) meter connector.
2. Connect terminals THA and E2 of the MAF meter wire harness side connector.
3. Connect an intelligent tester to the DLC3.
4. Turn the ignition switch ON.
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 : CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER

NG: Go to Next Step
READ VALUE OF INTELLIGENT TESTER (CHECK FOR OPEN IN ECM)
1. Disconnect the M1 MAF meter connector.
2. Connect terminals THA and E2 of the E4 ECM connector.
  HINT:
  
  Before checking, do visual and contact pressure checks on the ECM connector.
3. Connect an intelligent tester to the DLC3.
4. Turn the ignition switch ON.
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 : REPAIR OR REPLACE HARNESS OR CONNECTOR

NG: CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM
READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the M1 MAF meter connector.
2. Connect an intelligent tester to the DLC3.
3. Turn the ignition switch ON.
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.
  
  Fig 3: MAF Meter Connector Circuit
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
OK : REPLACE MASS AIR FLOW METER

NG: Go to Next Step
READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT ECM)
1. Disconnect the E4 ECM connector.
2. Connect an intelligent tester to the DLC3.
3. Turn the ignition switch ON.
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 ECM connector.
OK : REPAIR OR REPLACE HARNESS OR CONNECTOR

NG: REPLACE ECM