Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
1-36 Description and Operation
Engine Control Components
Typical MAPT Sensor
Mass Airflow (MAF) Sensor
The MAF sensor uses a hot wire sensing element to measure the amount of air entering the engine. Air passing over the hot wire causes it to cool. This hot wire is maintained at 200°C (392°F) above the ambient temperature as measured by a constant cold wire. The current required to maintain the temperature of the hot wire is proportional to the mass airflow. The MAF sensor then outputs a signal to the PCM proportional to the intake air mass. The PCM calculates the required fuel injector pulse width in order to provide the desired air to fuel ratio. This input is also used in determining transmission electronic pressure control (EPC), shift, and torque converter clutch (TCC) scheduling.
The MAF sensor is located near the air cleaner assembly. Most MAF sensors have an integrated IAT sensor.
Typical MAF Sensor
Output Shaft Speed (OSS) Sensor
The OSS sensor provides the PCM with the source of vehicle speed. The sensor may be physically located in different places on the vehicle, depending upon the specific application. The design of each speed sensor is unique and depends on which powertrain control feature uses the information that is generated.
Power Take Off (PTO) Switch And Circuits
The PTO circuit is used by the PCM to disable some of the OBD monitors during PTO operation. The PTO switch is normally open. When the PTO unit is activated, the PTO switch is closed and battery voltage is supplied to the PTO input circuit. This indicates to the PCM that an additional load is being applied to the engine. The PTO indicator lamp illuminates when the PTO system is functioning correctly and flashes when the PTO system is damaged.
When the PTO unit is activated, the PCM disables some OBD monitors which may not function reliably during PTO operation. Without the PTO circuit information to the PCM, false DTCs may be set during PTO operation. Prior to an inspection/maintenance (I/M) test, operate the vehicle with the PTO disengaged long enough to successfully complete the OBD monitors.
PTO Circuits Description
The 3 PTO input circuits are PTO mode, PTO engage, and PTO RPM.
2016 Powertrain Control/Emissions Diagnosis, Gasoline Engines, 3/2015
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.