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 power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / 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 

Fig 1: Inspect Mass Air Flow Meter Sub-Assembly (Power Source Voltage)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the mass air flow meter sub-assembly connector.
2. Turn the power switch on (IG).
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   D5-3 (+B) - Body ground	Power switch on (IG)	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

4. Reconnect the mass air flow meter sub-assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI MAIN RELAY - MASS AIR FLOW METER SUB-ASSEMBLY) 

OK: Go to next step 

1. Disconnect the mass air flow meter sub-assembly 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
   D5-5 (VG) - D28-94 (VG)	Always	Below 1 Ω
   D5-4 (E2G) - D28-117 (E2G)

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   D5-5 (VG) or D28-94 (VG) - Body ground	Always	10 kΩ or higher

4. Reconnect the mass air flow meter sub-assembly connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

OK: Go 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 sub-assembly.
   1. Connect the Techstream to the DLC3.
   2. Turn the power switch on (IG).
   3. Turn the Techstream on.
   4. Put the engine in inspection mode. Refer to INSPECTION MODE PROCEDURE .
   5. Enter the following menus: Powertrain / Engine and ECT / Data List / All Data / MAF.
   6. Start the engine.
   7. Check that the reading of the mass air flow meter sub-assembly changes when the engine is raced.

      OK

      The reading changes.

NG → See step   7 

OK → See step   8 

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

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   D5-4 (E2G) - Body ground	Always	Below 1 Ω

3. Reconnect the mass air flow meter sub-assembly connector.

NG → See step   6 

OK → See step   7 

1. Disconnect the mass air flow meter sub-assembly 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
   D5-4 (E2G) - D28-117 (E2G)	Always	Below 1 Ω

4. Reconnect the mass air flow meter sub-assembly connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER SUB-ASSEMBLY - ECM) 

OK → See step   8