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 / Data List / MAF.
5. Read the values displayed on the Techstream.

   Result

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

   *1: The value must be changed when the throttle valve is open or closed.

C → See step   12 

B → See step   9 

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. Inspect the output voltage.
   Fig 2: Identifying Mass Air Flow Meter Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Apply battery voltage across terminals +B and E2G.
   2. Connect the positive (+) tester probe to terminal VG, and negative (-) tester probe to terminal E2G.
   3. Measure the voltage between the terminals.

      Standard voltage

      Tester Connection	Specified Condition
      VG (B33-5) - E2G (B33-4)	0.2 to 4.9 V

NG → REPLACE MASS AIR FLOW METER 

OK: Go to next step 

1. Disconnect the B33 MAF meter connector.
   Fig 3: Identifying B33 MAF Meter Connector Terminal & B12 ECM Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 → REPLACE ECM 

1. Remove the EFI No. 3 fuse from the engine room R/B.
   Fig 4: Identifying Engine Room Relay Block & EFI No. 3

   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.
   Fig 5: Identifying B33 MAF Meter Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Remove the engine room junction block from the engine room R/B.
3. Measure the resistance between the terminals.

   Standard resistance (Check for open)

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

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   +B (B33-3) or 1E-6 (Engine room R/B) - 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 R/B.
   Fig 6: 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.

NG → REPLACE ENGINE ROOM JUNCTION BLOCK 

OK → See step   8 

1. Disconnect the B33 MAF meter connector.
   Fig 7: Identifying B33 MAF Meter Connector Terminal & E2G

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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   13 

NG: Go to next step 

1. Disconnect the B33 MAF meter connector.
   Fig 8: Identifying Mass Air Flow Meter And ECM Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 → See step   11