DTC P0102 Mass Air Flow Circuit Low Input (4JJ3 without DPD)

1. DTC P0102 description

The MAF sensor is an air flow meter that measures the amount of air that enters the engine. It is installed between the air cleaner and the turbocharger. When the amount of air entering the engine is small, it indicates deceleration or idling speed. When the amount of air entering the engine is large, it indicates acceleration or a high load state. The sensor has the following circuits.

  • Ignition power supply circuit
  • Low reference circuit
  • MAF sensor signal circuit

The ECM monitors the MAF sensor signal voltage. The scan tool displays this output voltage in voltage and grams per cylinder (g/cyl). If the ECM detects an excessively low signal voltage, the DTC is set.

2. Condition for setting DTC P0102

Condition for running the DTC

  • The battery voltage is 10 to 16 V.
  • The ignition switch is ON.
  • The engine is running.
  • DTCs P0560 and P060B are not set.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P0560 System Voltage".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC P060B Internal Control Module A/D Processing Performance".

Condition for setting the DTC

  • The ECM detects that the MAF sensor signal voltage is 0.1 V or less for 3 seconds.

3. Action taken when DTC P0102 sets

  • Euro4: The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type A (Euro4).
  • Except Euro4: The ECM illuminates the check engine warning light. Refer to Action taken when DTC sets - Type A (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC type definitions".

  • The ECM limits the fuel injection quantity.
  • The ECM inhibits pre-injection.
  • The ECM inhibits the EGR control.
  • The ECM inhibits the cruise control.
  • The ECM assumes a default MAF value.

4. Condition for clearing DTC P0102

  • Euro4: Refer to Condition for clearing the MIL/DTC - Type A or Type B (Euro4).
  • Except Euro4: Refer to Condition for clearing the check engine warning light/DTC - Type A or Type B (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) DTC type definitions".