How to determine if an oxygen sensor signal wire is open or shorted to ground on a system that doesn't use a bias voltage. 2005 Mercury Sable 3.0 with a P2270 trouble code

Engine Performance Diagnostics chapter 5 page 23

symptoms 50

  • check engine light with a P2270 trouble code
  • O2 signal stuck lean

fix 50

  • replace faulty oxygen sensor

test shown enh 50

  • how to force a rich condition to check a stuck lean O2 signal
  • sensor side color review for quick identification
  • how to test oxygen sensor wiring integrity using a test light

Tools used

  • scan tool
  • jumper wire
  • LED test light
  • incandescent test light
  • digital multimeter

end faq

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


(Chapters 4 and 5) Fuel Trim and Oxygen Sensor Testing

Related videos:

How to quickly test an oxygen sensor circuit (GM bias voltage):


What can cause an O2 sensor to read near 5 volts? (Chrysler bias voltage):


O2 sensor circuit testing (a ScannerDanner Premium video):


O2 sensor testing (fixed lean) P0174, P0154, P0155 (Mitsubishi) :


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!