P0100 (blink 31) on Toyota Corolla E120: MASS AIR FLOW CIRCUIT MALFUNCTION

Short answer: P0100 means “MASS AIR FLOW CIRCUIT MALFUNCTION”. The car’s computer has found a fault in the EFI 1NZ-FE/2NZ-FE system and turns on the Malfunction indicator lamp (Check Engine). First 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).

Code

P0100 · blink 31

System

EFI 1NZ-FE/2NZ-FE

Dashboard light

Malfunction indicator lamp (Check Engine)

Applies to

2NZ-FE 1.3 (PK XLi/GLi NZE120) and 1NZ-FE 1.5 (JDM NZE121/NZE124 Corolla/Fielder/Runx)

Confidence

high (official Toyota RM821E)

Source

toyotamanuals.gitlab.io

Symptoms and when it is set

1. Open or short in air flow meter circuit with more than 3 sec. engine speed less than 4,000 rpm

Likely causes

1. Open or short in air flow meter circuit; Air flow meter; Engine ECU

What to check, in order

1. 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)

Related on this car

• Dirty MAF sensor
• All fault codes for this car
• Warning lights
• Where the parts are (parts map)
• Common problems

Same code on other cars

• P0100 · Toyota Corolla (11th gen, E170)
• P0100 · Toyota Corolla (10th gen, E140)
• P0100 · Honda City (5th gen, GM2)
• P0100 · Honda Civic (10th gen, FC)
• P0100 · Suzuki Wagon R (Pakistan, K10B)
• P0100 on all cars compared

← P1790/65 P0110/24 →

Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.