Inspection Procedure

HINT:

If DTCs related to different system that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.

Connect hand-held tester or OBD II scan tool, and read value of intake air temperature.
PREPARATION:
1. Connect the hand-held tester or the OBD II scan tool to the DLC3.
2. Turn the ignition switch to ON and turn the hand-held tester or the OBD II scan tool main switch ON.
3. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".
CHECK:

Read the temperature value on the hand-held tester or the OBD II scan tool.

OK:
1. Same value as actual intake air temperature
HINT:
- If there is open circuit, the hand-held tester or the OBD II scan tool indicates -40°C (-40°F).
- If there is short circuit, the hand-held tester or the OBD II scan tool indicates 140°C (284°F) or more.
1. NG: -40 °C (-40°F) Go to step 2. 140°C (284°F) or more Go to step 4 .
2. OK: Check for intermittent problems (See PRE-CHECK ).
Check for open in harness or ECM.
PREPARATION:
1. Disconnect the MAF meter connector.
2. Connect the sensor wire harness terminals together.
3. Turn the ignition switch to ON.
4. Select the Item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".
CHECK:

Read the temperature value on the hand-held tester or the OBD II scan tool.

OK:
1. Temperature value: 140°C (284°F) or more
Fig 1: Disconnecting MAF Meter Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Confirm good connection at sensor. If OK, replace mass air flow meter.
2. NG: Go to next step.
Check for open in harness or ECM.
PREPARATION:
1. Disconnect the MAF meter connector.
2. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
3. Connect terminals THA and E2 of the ECM connector together.
4. Turn the ignition switch to ON.
5. Select the Item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".
HINT:

The MAF meter connector is disconnected. Before checking, do a visual and contact check of the pressure of the ECM connector (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).

CHECK:

Read the temperature value on the hand-held tester or the OBD II scan tool.

OK:
1. Temperature value: 140°C (284°F) or more
Fig 2: Connecting Terminal THA And E2 Of ECM connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Open in harness between terminals E2 and THA, repair or replace harness.
2. NG: Confirm good connection at ECM. If OK, replace ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
Check for short in harness and ECM.
PREPARATION:
1. Disconnect the MAF meter connector.
2. Turn the ignition switch to ON.
3. Select the Item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".
CHECK:

Read the temperature value on the hand-held tester or the OBD II scan tool.

OK:
1. Temperature value: - 40°C (-40°F)
Fig 3: Disconnecting MAF Meter To Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Replace mass air flow meter.
2. NG: Go to next step.
Check for short in harness or ECM.
PREPARATION:
1. Remove the glove compartment (See ENGINE CONTROL MODULE (ECM) ).
2. Disconnect the E7 ECM connector.
  HINT:
  
  The MAF meter connector is disconnected.
3. Turn the ignition switch to ON.
4. Select the Item "DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL/INTAKE AIR".
CHECK:

Read the temperature value on the hand-held tester or the OBD II scan tool.

OK:
1. Temperature value: - 40°C (-40°F)
Fig 4: Disconnecting E7 Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Repair or replace harness or connector.
2. NG: Replace ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).