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. Enter the following menus: Powertrain / Engine / Trouble Codes.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC P0102 is output	A
   DTC P0103 is output	B

B → See step   6 

A: Go to next step 

1. Disconnect the E29 Mass Air Flow (MAF) meter connector.
   Fig 1: E29 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 (E29-3) - Body ground	9 to 14 V

4. Reconnect the MAF meter connector.

NG → See step   5 

OK: Go to next step 

1. Disconnect the E29 MAF meter connector.
2. Disconnect the E5 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   VG (E29-5) - VG (E5-27)	Below 1 Ω
   E2G (E29-4) - E2G (E5-26)	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   VG (E29-5) or VG (E5-27) - 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. 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. Check that the reading of the mass air flow meter changes when the engine is raced.

      OK

      The reading changes.

NG → REPLACE MASS AIR FLOW METER 

OK → See step   8 

1. Inspect the EFI NO. 2 fuse.
   1. Remove the EFI NO. 2 fuse from the engine room R/B No. 2.
   2. Check the EFI NO. 2 fuse resistance.

      Standard resistance

      Below 1 Ω

   3. Reinstall the EFI No. 2 fuse.
2. Disconnect the E29 MAF meter connector.
3. Remove the integration relay from the engine room R/B No. 2.
4. Measure the resistance according to the value(s) in the table below.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   +B (E29-3) - 2A-8	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   +B (E29-3) or 2A-8 - Body ground	10 kΩ or higher

5. Reconnect the MAF meter connector.
6. Reinstall the integration relay.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → CHECK ECM POWER SOURCE CIRCUIT 

1. Measure the resistance according to the value(s) in the table below.
   Fig 2: Identifying ECM Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance

   Tester Connection	Specified Condition
   E2G (E5-26) - Body ground	Below 1 Ω

NG → See step   8 

OK: Go to next step 

1. Disconnect the E29 MAF meter connector.
2. Disconnect the E5 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance (Check for open)

   Tester Connection	Specified Condition
   VG (E29-5) - VG (E5-27)	Below 1 Ω
   E2G (E29-4) - E2G (E5-26)	Below 1 Ω

   Standard resistance (Check for short)

   Tester Connection	Specified Condition
   VG (E29-5) or VG (E5-27) - 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 MASS AIR FLOW METER