Inspection Procedure

1. Connect the intelligent tester or the OBD II scan tool to the DLC3.
2. Start the engine.
3. Push the intelligent tester or the OBD II scan tool main switch ON.
4. On the intelligent tester or the OBD II scan tool, enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / MAF. Read the values.

Result 

HINT:

*: The value must change when the throttle valve is opened or closed.

B : GO TO STEP   6 

C : CHECK FOR INTERMITTENT PROBLEMS 

A : Go to next step 

1. Turn the ignition switch ON.
2. Disconnect the M1 MAF meter connector.
3. Measure the voltage of the wire harness side connector.

Standard voltage 

Fig 1: Inspecting Mass Air Flow Meter (Power Source Voltage)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : GO TO STEP   5 

OK : Go to next step 

1. Start the engine.
2. Measure the voltage of the E8 ECM connector.

HINT:

The shift position should be P or N and the A/C switch should be turned OFF.

Standard voltage 

Fig 2: Inspecting ECM (VG Voltage)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : REPLACE ECM 

NG : Go to next step 

1. Disconnect the M1 MAF meter connector.
2. Disconnect the E8 ECM connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   MASS AIR FLOW METER - ECM
   
   

   Tester Connection	Specified Condition
   M1-3 (VG) - E8-30 (VG) M1-2 (E2G) - E8-29 (E2G)	Below 1 Ω
   M1-3 (VG) or E8-30 (VG) - Body ground	10 kΩ or higher

4. Reconnect the MAF meter connector and ECM connector.
Fig 3: Checking Harness And Connector (Mass Air Flow Meter - ECM)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK : REPLACE MASS AIR FLOW METER 

1. Check the EFI No. 2 fuse.
   1. Remove the EFI No. 2 fuse the fusible link block.
   2. Measure the resistance of the EFI No. 2 fuse.

      Standard: Below 1 Ω 

   3. Reinstall the EFI No. 2 fuse.
2. Disconnect the M1 MAF meter connector.
3. Remove the EFI MAIN relay from the engine room R/B.
4. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   MASS AIR FLOW METER - EFI MAIN RELAY
   
   

   Tester Connection	Specified Condition
   M1-1 (+B) - EFI MAIN relay terminal 3	Below 1 Ω
   M1-1 (+B) or EFI MAIN relay terminal 3 - Body ground	10 kΩ or higher

   Fig 4: Checking Harness And Connector (Mass Air Flow Meter - EFI Main Relay)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
5. Reconnect the MAF meter connector.
6. Reinstall the EFI MAIN relay.

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK : INSPECT ECM POWER SOURCE CIRCUIT 

1. Measure the resistance of the ECM connector.

Standard resistance 

Fig 5: Inspecting ECM (Sensor Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG : REPLACE ECM 

OK : Go to next step 

1. Disconnect the M1 MAF meter connector.
2. Disconnect the E8 ECM connector.
3. Measure the resistance of between the wire harness side connectors.

   Standard resistance 

   MASS AIR FLOW METER - ECM
   
   

   Tester Connection	Specified Condition
   M1-3 (VG) - E8-30 (VG) M1-2 (E2G) - E8-29 (E2G)	Below 1 Ω
   M1-3 (VG) or E8-30 (VG) - Body ground	10 kΩor higher

   Fig 6: Checking Harness And Connector (Mass Air Flow Meter - ECM)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Reconnect the MAF meter connector and ECM connector.

NG : REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK : REPLACE MASS AIR FLOW METER