Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Using hand-held tester or scan tool, read FREEZE FRAME data. Freeze frame data records engine conditions when malfunction is detected.

After confirming DTC P0100, P0102 or P0103, use the hand-held tester or the OBD II scan tool to confirm the mass air flow ratio from the DIAGNOSIS/ENHANCED OBD II/DATA LIST/ALL. If MAF meter air flow rate is 0.0 gm/sec., VG circuit may be open or shorted, or power source circuit may be open. If MAF meter air flow rate is 271.0 gm/sec. or more with engine idling and at normal operating temperature, E2G circuit may be open.

For circuit wiring diagram, diagnosis and repair procedure, see Fig 1, Fig 2 & Fig 3 .

For ECM location, see Figure. For ECM connector view, see Figure. For testing of systems or components, see SYSTEM & COMPONENT TESTING - V6 & V8 article. For removal and installation of components, see REMOVAL & INSTALLATION - V6 & V8 article.

Fig 1: DTCs P0100, P0102 & P0103 Diagnostic Procedure (Steps 1-3)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 2: DTCs P0100, P0102 & P0103 Diagnostic Procedure (Steps 4-5)

Fig 3: DTCs P0100, P0102 & P0103 Diagnostic Procedure (Step 5 Cont. & Steps 6-7)

Fig 4: Identifying Mass Airflow Meter Connector Terminals