P1100 - FAULT CODE - OBD2

P1100 FORD, LINCOLN, MAZDA, MERCURY: MASS AIR FLOW SENSOR INTERMITTENT

The MAF (Mass Air Flow Sensor) measures and reports how much air enters the engine. This data is transmitted to the PCM (Powertrain Control Module), which will use it to determine the engine load.

Although there are several designs of the MAF sensor, the most common is the hot wire design. There are two wires, one of them is heated and the other is not. A microprocessor inside the sensor determines the amount of air entering the motor by the amount of current required for the wire to be about 200°F hotter than the cold wire. Each time the temperature difference between the two wires varies, the sensor increases or decreases the current to the hot wire. This means more air or less air in the motor.

The MAF sensor circuit is continuously monitored by the PCM for sudden changes in voltage input or airflow. If during the last 40 warm-up cycles the PCM detects a voltage change far above or far below the calibrated limit, the P1100 OBDII fault code will be set.

• Check Engine light ON.
• Problems starting the engine.
• Motor stalling.

The P1100 OBD2 diagnostic code is stored for these reasons:

• Before or after the installation of the MAF sensor, air leakage may occur.
• The Mass Air Flow Sensor circuit may have deficiencies in the wiring or connectors.
• The MAF sensor may be in poor condition.

To troubleshoot DTC P1100 OBDII faults, you must try this:

• First, consult the Technical Service Bulletins.
• Verify that there are no air leaks around the MAF sensor. If such variations are found, make corrections.
• Check all the Mass Air Flow Sensor wiring and connectors for deficiencies caused by burns, corrosion, or wear. Repair or replace components as required.
• Perform voltage tests to the MAF Sensor circuit, follow the steps given by the manufacturer on the vehicle's data source. Repair if necessary.
• Check the integrity of the MAF sensor. If you determine that it is faulty, replace it.