Do not change your purge solenoid or any other components without first checking your gas cap! The manufacturer doesn't list EVAP leaks (loose gas cap), as one of the causes of this code, so it is no wonder so many people are having issues.

Engine Performance Diagnostics chapter 3

Topics discussed


  • check engine light on (P0441 trouble code)

fix 50

  • tighten loose gas cap

Tools used

end faq

{accordionfaq faqid=accordion15 faqclass="dotluvfaq help2 aligncenter headerbackground headerborder contentbackground contentborder round7" active=item0}


(Chapter 3) Transistors, Solenoids, Computer Controlled Output Testing

Related videos:

Understanding Short Term and Long Term Fuel Trim (an SD Premium video):


How to test a purge solenoid (Mazda P0443, P0455):


How to test a computer controlled solenoid - power/ground side identification:


end faq

{accordionfaq faqid=accordion3 faqclass="darkhivefaq defaulticon headerbackground headerborder contentbackground contentborder round5" active=item0}

For more information on this topic, I have written a “field manual” called Engine Performance Diagnostics which is available as an eBook or paper book.

Want even more diagnostic training? Whether you are a DIY trying to fix your own car, someone looking to become an auto technician, or a current auto technician that wants to get more into diagnostics, subscribe to ScannerDanner Premium. There is a 14 day free trial.

On ScannerDanner Premium I will bring you right into my classroom at Rosedale Technical College. You will find page for page lectures taken right from my book as well as exclusive classroom type case studies. What is so special about these classroom case studies? I pull live problem vehicles directly into my classroom and we troubleshoot them in real time, using and applying the theory and testing procedures we learn during the classroom lectures. There is no better on-line training of how to troubleshoot automotive electrical and electronics systems anywhere!