LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Porsche >> 1993 >> 911 America, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Fault Code Diagnosis & Testing >> Code 1121: Airflow Sensor
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Code 1121: Airflow Sensor

  1. Voltage Supply

    Connect DVOM between ground and terminal No. 3 of airflow sensor wiring harness connector. See Fig 1 . Turn ignition on to check voltage supply to sensor. If reading is 4.7-5.3 volts, go to next step. If voltage is not 4.7-5.3 volts, check Blue/Green wire back to DME control unit.
  2. Voltage Drop

    Disconnect air filter hose. Using jumper wires, connect terminal No. 3 of airflow sensor wiring harness connector to terminal No. 3 of sensor, and connect terminal No. 4 of wiring harness connector to terminal No. 4 of sensor.
  3. Connect DVOM between ground and airflow sensor terminal No. 2. Turn ignition on to check voltage drop across sensor. With airflow sensor plate closed, reading should be 250-260 millivolts.
  4. Using screwdriver handle, press airflow sensor plate to full throttle position. Reading should gradually increase to about 4.6 volts. If voltage values are incorrect, replace airflow sensor.
Fig 1: Identifying Airflow Sensor Terminals
G91D16496