Inspection Procedure

WARNING: This page is about a different car, the 2007 Lexus RX 350. However, it is still accessible from the selected car via links, so may be relevant.

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 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.

READ VALUE OF INTELLIGENT TESTER (INTAKE AIR TEMPERATURE)

Connect the intelligent tester to the DLC3.
Turn the ignition switch to the ON position.
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 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, 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 the intelligent tester to the DLC3.
4. Turn the ignition switch to the ON position.
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 (See REMOVAL )

Fig 1: Checking For Open In MAF Meter Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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 E8 ECM connector.
  HINT:
  
  Before checking, do visual and contact pressure checks on the ECM connector.
3. Connect the intelligent tester to the DLC3.
4. Turn the ignition switch to the ON position.
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

Fig 2: Checking For Open In ECM Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: CONFIRM GOOD CONNECTION TO ECM. IF OK, REPLACE ECM (See REMOVAL )
READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN WIRE HARNESS)
1. Disconnect the M1 MAF meter connector.
2. Connect the intelligent tester to the DLC3.
3. Turn the ignition switch to the ON position.
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.
OK: CONFIRM GOOD CONNECTION TO SENSOR. IF OK, REPLACE MASS AIR FLOW METER (See REMOVAL )

Fig 3: Checking For Short In MAF Meter Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Go to Next Step
READ VALUE OF INTELLIGENT TESTER (CHECK FOR SHORT IN ECM)
1. Disconnect the E8 ECM connector.
2. Connect the intelligent tester to the DLC3.
3. Turn the ignition switch to the ON position.
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

Fig 4: Checking For Short In ECM Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE ECM (See REMOVAL )