EGR Monitor PCM monitors by change in Short Term Fuel Trim
{"Image DocumentName": "EGR Monitor PCM monitors by change in Short Term Fuel Trim", "Image ImageDescription": "During operation of the EGR system the PCM will momentarily shut down the EGR solenoid. As a result EGR flow stops and a lean condition occurs. HO2S voltage will drop. STFT sees HO2S voltage drop and increases IPW. The PCM monitors STFT and EGR monitor is complete & Ready. The PCM runs the EGR monitor by doing these functions: EGR Solenoid is turned off. O2 Compensation is monitored. When the EGR is turned off the air/fuel mixture shifts lean if due to more air flowing in the system. The O2 sensor will indicate a leaner mixture by decreasing the voltage output of the sensor. Short Term fuel trim will shift rich to increase pulse-width of the injector. By monitoring the changes the PCM indirectly monitors the EGR system. Chrysler systems will set a maturing code (Pending Code) along with a Freeze Frame. On the second consecutive trip with a failure the MIL is turned on and a DTC is set along with a Freeze Frame.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}