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.
1-68 Description and Operation
Exhaust Gas Recirculation (EGR) Systems
Exhaust Gas Recirculation (EGR) Systems
Overview
The EGR system controls the nitrogen oxides (NO ) emissions. Small amounts of exhaust gases are recirculated back into the combustion
x
chamber to mix with the air to fuel charge. The combustion chamber temperature is reduced, lowering NO emissions.
x
Electric Exhaust Gas Recirculation (EEGR) System
The EEGR system consists of an electric motor EGR valve integrated assembly, a manifold absolute pressure (MAP) sensor, PCM, and connecting wiring. For additional information on the EGR system components, refer to Engine Control Components in this section. Operation of the system is as follows:
1. The EEGR system receives signals from the engine coolant temperature (ECT) or cylinder head temperature (CHT) sensor, throttle position (TP) sensor, mass airflow (MAF) sensor, crankshaft position (CKP) sensor, and the MAP sensor to provide information on engine operating conditions to the PCM. The engine must be warm, stable, and running at a moderate load and RPM before the EEGR system is activated. The PCM deactivates the EEGR during idle, extended wide open throttle (WOT), or whenever a concern is detected in an EEGR component or EGR required input.
2. The PCM calculates the desired amount of EGR for a given set of engine operating conditions.
3. The PCM in turn outputs signals to control the EEGR motor to move (advance or retract) a calibrated number of discrete steps. The electric stepper motor directly actuates the EEGR valve, independent of engine vacuum. The EEGR valve is commanded from 0 to 52 discrete steps to get the EGR valve from a fully closed to a fully open position. The position of the EGR valve determines the EGR flow.
4. A MAP sensor measures variations in manifold pressure as exhaust gas recirculation is introduced into the intake manifold. Variations in EGR being used correlate to the MAP signal (increasing EGR increases manifold pressure values).
EEGR System
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.