DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input: Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine / Trouble Codes.
5. Read the DTCs.
   RESULT
   
   

   Result	Proceed to
   DTC P0102 is output	A
   DTC P0103 is output	B

B → See step   5 

A: Go to next step 

1. Disconnect the mass air flow meter connector.
   Fig 1: Checking B4 Mass Air Flow Meter Sub-Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   B4-3 (+B) - Body ground	Ignition switch ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Mass Air Flow Meter)

NG → See step   7 

OK: Go to next step 

1. Disconnect the mass air flow meter connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   B4-5 (VG) - B1-74 (VG)	Always	Below 1 Ω
   B4-4 (E2G) - B1-75 (E2G)	Always	Below 1 Ω
   B4-5 (VG) or B1-74 (VG) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Inspect the mass air flow meter, referring to the On-vehicle Inspection for Mass Air Flow Meter. Refer to ON-VEHICLE INSPECTION .
2. Inspect the mass air flow meter, referring to the Inspection for Mass Air Flow Meter. Refer to INSPECTION .
3. Inspect the function of the mass air flow meter.
   1. Connect the Techstream to the DLC3.
   2. Turn the ignition switch to ON.
   3. Turn the Techstream on.
   4. Enter the following menus: Powertrain / Engine / Data List / MAF.
   5. Start the engine.
   6. Check that the reading of the mass air flow meter changes when the engine is raced.

      OK

      The reading changes.

NG → See step   8 

OK → See step   9 

1. Disconnect the mass air flow meter connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   B4-4 (E2G) - Body ground	Always	Below 1 Ω

NG → See step   6 

OK → See step   8 

1. Disconnect the mass air flow meter connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   B4-4 (E2G) - B1-75 (E2G)	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   9 

1. Disconnect the mass air flow meter connector.
2. Remove the EFI MAIN relay from the engine room relay block.
3. Measure the resistance according to the value(s) in the table below.

   Tester Connection	Condition	Specified Condition
   B4-3 (+B) - 3 (EFI MAIN relay holder)	Always	Below 1 Ω
   B4-3 (+B) or 3 (EFI MAIN relay holder) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   10