DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input [08/2015 - 08/2019]: 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
   
   

   Mass Air Flow Rate (g/sec.)	Proceed to
   0.0	A
   271.0 or more	B
   Between 1.0 and 270.0*1	C

   HINT: 

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

Result: 

B 

See step  6

Result: 

C 

CHECK FOR INTERMITTENT PROBLEMS 

(Refer to CHECK FOR INTERMITTENT PROBLEMS [08/2015 - ] )

Result: 

A 

See step  2

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	Condition	Specified Condition
   B35-3 (+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.

Result: 

NG 

See step  5

Result: 

OK 

See step  3

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
   B35-5 (VG) - B37-14 (VG)	Always	Below 1 Ω
   B35-4 (E2G) - B37-13 (E2G)	Always	Below 1 Ω
   B35-5 (VG) or B37-14 (VG) - Body ground	Always	10 kΩ or higher

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

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  4

1. Inspect the mass air flow meter (Refer to ON-VEHICLE INSPECTION [08/2015 - ] ).

Result: 

OK 

REPLACE ECM 

(Refer to REMOVAL [08/2015 - ] )

Result: 

NG 

REPLACE MASS AIR FLOW METER 

(Refer to REMOVAL [08/2015 - ] )

1. Disconnect the mass air flow meter connector.
2. Remove the No. 1 integration relay from the engine room relay block.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   B35-3 (+B) - 1D-4	Always	Below 1 Ω
   B35-3 (+B) or 1D-4 - Body ground	Always	10 kΩ or higher

4. Reconnect the mass air flow meter connector.
5. Reinstall the No. 1 integration relay.

Result: 

OK 

CHECK ECM POWER SOURCE CIRCUIT 

(Refer to ECM Power Source Circuit [08/2015 - 08/2019] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

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
   B35-4 (E2G) - Body ground	Always	Below 1 Ω

Result: 

OK 

REPLACE MASS AIR FLOW METER 

Result: 

NG 

See step  7

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
   B35-5 (VG) - B37-14 (VG)	Always	Below 1 Ω
   B35-4 (E2G) - B37-13 (E2G)	Always	Below 1 Ω
   B35-5 (VG) or B37-14 (VG) - Body ground	Always	10 kΩ or higher

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

Result: 

OK 

REPLACE ECM 

(Refer to REMOVAL [08/2015 - ] )

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR