EGR Closed Performance P1404 with new EGR valve installed (GM)

During this diagnosis of an EGR trouble code on this Impala, I have the opportunity to go into detail about computer controlled solenoids, duty cycle, and how they relate to valve position. I also get to showcase the power of the Verus, with side-by-side scope and scan tool testing. Despite the inadvertent fix, this video makes for great study material, especially relating to sections 3, 7 and 20 in my book.

Engine Performance Diagnostics chapter 3

Symptoms
- check engine light (P1404)

Fix
- resetting the EGR valve closed position voltage (by disconnecting the battery)

Tests shown
- using a bi-directional test to command an EGR valve to open/close
- how to use scan data to evaluate an EGR valve position error
- using a wiring diagram to understand circuit design
- how to view the scope and scan tool simultaneously on the Snap-On Verus
- understanding duty cycle control and frequency, relating to power/ground switching
- how to distinguish between a duty cycle command and valve position
- how to clean the valve seat on a GM linear EGR valve
- checking an EGR valve position sensor and wiring with a scope
- how to reset the EGR closed position voltage in the PCM
- how to identify an incorrectly installed (reversed) EGR valve with scan data

Tools used
- scan tool
- lab scope

Playlist
- (Chapter 3) Transistors, Solenoids, Computer Controlled Output Testing
   • (Chapter 3) Transistors, Solenoids, C...  

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For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available at www.scannerdanner.com as an eBook or paper book.
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Due to factors beyond the control of ScannerDanner LLC, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. ScannerDanner LLC assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. ScannerDanner LLC recommends safe practices when working with power tools, automotive lifts, lifting tools, jack stands, electrical equipment, blunt instruments, chemicals, lubricants, or any other tools or equipment seen or implied in this video. Due to factors beyond the control of ScannerDanner LLC, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Any injury, damage or loss that may result from improper use of these tools, equipment, or the information contained in this video is the sole responsibility of the user and not ScannerDanner LLC.