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. Start the engine.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.
5. Read the values displayed on the Techstream.
   RESULT
   
   

   MAF (gm/sec)	Refer to
   0.0	A
   271.0 or more	B
   Between 1.0 and 270.0*	C

   HINT: 

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

B → Refer to step   6 

C → Refer to step   8 

A: Refer to next step 

Fig 1: Identifying Mass Air Flow Meter Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the mass air flow meter connector.
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
   C23-3 (+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)

4. Reconnect the mass air flow meter connector.

NG → Refer to step   5 

OK: Refer 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 (Check for Open)

   Tester Connection	Condition	Specified Condition
   C23-5 (VG) - C19-118 (VG)	Always	Below 1 Ω
   C23-4 (E2G) - C19-116 (E2G)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   C23-5 (VG) or C19-118 (VG) - Body ground	Always	10 kΩ or higher

4. Reconnect the mass air flow meter connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Refer to next step 

1. Perform On-vehicle Inspection. Refer to ON-VEHICLE INSPECTION .
2. Perform Inspection. Refer to INSPECTION .
3. Inspect the function of the mass air flow meter.
   1. Remove the mass air flow meter with the connector connected.
   2. Connect the Techstream to the DLC3.
   3. Turn the ignition switch to ON.
   4. Turn the Techstream on.
   5. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.
   6. Check that the mass air flow meter value changes when the engine is raced.

      OK

      The reading changes.

NG → Refer to step   9 

OK → Refer to step   10 

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

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   C23-3 (+B) - 1A-4	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   C23-3 (+B) or 1A-4 - Body ground	Always	10 kΩ or higher

4. Reinstall the integration relay.
5. Reconnect the mass air flow meter connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → Refer to step   11 

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
   C23-5 (VG) - C19-118 (VG)	Always	Below 1 Ω
   C23-4 (E2G) - C19-116 (E2G)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   C23-5 (VG) or C19-118 (VG) - Body ground	Always	10 kΩ or higher

4. Reconnect the mass air flow meter connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Refer to next step 

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

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   C23-4 (E2G) - Body ground	Always	Below 1 Ω

3. Reconnect the mass air flow meter connector.

NG → Refer to step   12 

OK → Refer to step   13