P0100 · blink 31 – MASS AIR FLOW CIRCUIT MALFUNCTION
- System
- EFI 3ZZ-FE
- Dashboard light
- Malfunction indicator lamp (Check Engine)
- Check-engine blink code
- 31
- Applies to
- 3ZZ-FE 1.6 (PK SE Saloon 1.6 2002-05 ZZE121)
- Description
- MASS AIR FLOW CIRCUIT MALFUNCTION
- Detection / symptoms
- Detection: Open or short in air flow meter circuit with more than 3 sec. engine speed less than 4,000 rpm
- Possible causes
- Open or short in air flow meter circuit; Air flow meter; Engine ECU
- What to check
- Workshop check order (RM821E): READ VALUE OF MAF/AFM -> INSPECT INTAKE AIR FLOW METER SUB−ASSY(POWER SOUCE VOLTAGE) -> INSPECT ECU -> CHECK HARNESS AND CONNECTOR(ENGINE ECU−AIR FLOW METER) -> CHECK HARNESS AND CONNECTOR(AIR FLOW METER +B CIRCUIT) -> INSPECT INTAKE AIR FLOW METER SUB−ASSY(POWER SOURCE VOLTAGE)
- Confidence
- high (official Toyota RM821E)
From the factory service material. Clear the code and test-drive to confirm it returns. Search all fault codes · Common problems · Warning lights

