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 engine switch on (IG).
3. Turn the Techstream on.
4. Select the following menu items: Powertrain / Engine / Trouble Codes.
5. Read the DTC.

   Result

   Display (DTC Output)	Proceed to
   P0102	A
   P0103	B

B → See step   8 

A: Go to next step 

1. Disconnect the B33 mass air flow (MAF) meter connector.
   Fig 1: Identifying B33 Mass Air Flow (MAF) Meter Connector

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

   Standard voltage

   Tester Connection	Specified Condition
   +B (B33-3) - Body ground	9 to 14 V

4. Reconnect the MAF meter connector.

NG → See step   5 

OK: Go to next step 

1. Disconnect the B33 MAF meter connector.
2. Disconnect the B12 ECM connector.
3. Measure the resistance between the terminals.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   VG (B12-72) - VG (B33-5)	Below 1 Ω
   E2G (B12-73) - E2G (B33-4)	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   VG (B12-72) or VG (B33-5) - Body ground	10 kΩ or higher

4. Reconnect the MAF meter connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Perform On-vehicle Inspection. Refer to ON-VEHICLE INSPECTION .
2. 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 engine switch on (IG).
   4. Turn the Techstream on.
   5. Enter the following menus: Powertrain / Engine / Data List / MAF.
   6. Blow air to the mass air flow meter and check that the intake air amount reading changes.

      OK

      The reading changes.

NG → See step   10 

OK: REPLACE ECM 

1. Remove the EFI No. 3 fuse from the engine room relay block.
   Fig 2: Identifying EFI No. 3 Fuse

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the EFI No. 3 fuse resistance.

   Standard resistance

   Below 1 Ω

3. Reinstall the EFI No. 3 fuse.

NG → REPLACE EFI NO. 3 FUSE 

OK: Go to next step 

1. Disconnect the B33 MAF meter connector.
2. Remove the engine room junction block from the engine room relay block.
3. Measure the resistance between the terminals.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   +B (B33-3) - 1E-6 (Engine room junction block)	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   +B (B33-3) or 1E-6 (Engine room junction block) - Body ground	10 kΩ or higher

4. Reinstall the engine room junction block.
5. Reconnect the B33 MAF meter connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the engine room junction block from the engine room relay block.
   Fig 3: Identifying Engine Room Junction Block & Engine Room Relay Block

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Inspect the EFI relay.
   1. Measure the EFI relay resistance.

      Standard resistance

      Tester Connection	Specified Condition
      1E-12 - 1E-6	10 kΩ or higher
      1E-12 - 1E-6	Bellow 1 Ω (Apply battery voltage between terminals 1E-9 and 1E-10)

3. Reinstall the engine room junction block.

OK → See step   11 

NG: REPLACE ENGINE ROOM JUNCTION BLOCK 

1. Disconnect the B33 MAF meter connector.
2. Measure the resistance between the terminals.

   Standard resistance

   Tester Connection	Specified Condition
   E2G (B33-4) - Body ground	Below 1 Ω

3. Reconnect the MAF meter connector.

OK → See step   10 

NG: Go to next step 

1. Disconnect the B33 MAF meter connector.
2. Disconnect the B12 ECM connector.
3. Measure the resistance between the terminals.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   E2G (B12-73) - E2G (B33-4)	Below 1 Ω

4. Reconnect the MAF meter connector.
5. Reconnect the ECM connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE ECM