1996 Jeep No Start Case Study Part I

Here is part II https://www.youtube.com/watch?v=jLwNcgtv9z0 Here is part III https://www.youtube.com/watch?v=dCZdv-FYwxw This is a three part series (10 minutes each) on a Jeep that has a no start, no spark, no injector pulse, no communication problem. We brought this case study into the classroom during a period when I was teaching my students about "The 5v reference circuit" (Chapter 9 in my book). Our approach in troubleshooting this problem is focused on the missing 5v reference. As you will find out in the end, it is simply a blown fuse for the ECM, however the procedures I show on how to test this 5v reference circuit can be applied to every single car out there. Be sure to watch the "Related videos" posted in this description for other case studies that actually have a shorted 5v reference circuit. Symptoms: - no start - cranks normally - no spark - no injector pulse - fuel pump runs continuously with key on - no check engine light Fix: - replace blown ECM fuse and repaired shorted oxygen sensor wiring Testing procedures shown: - how to check the 5v reference circuit - how to determine if the engine computer is "alive" or "dead" by using the 5v reference circuit as a guide - how to test a circuit for a short to ground - how to test for a shorted sensor - how to locate and repair a short to ground in the wiring harness of a car Tools used: - Scan tool - digital multimeter - incandescent test light - wire cutters - soldering gun - solder - heat shrink - short circuit tester Related videos: - Part II of this series https://youtu.be/jLwNcgtv9z0 - Part III of this series https://youtu.be/dCZdv-FYwxw - No Start from a shorted MAP sensor (Honda, Acura) https://youtu.be/za13UnpbH7E - How to check the 5v reference circuit for a short to ground https://youtu.be/uyncVz_HAtA - Bad Engine Computer Testing Part 1 https://youtu.be/hJQ6qnhTgdg - Bad Engine Computer Testing Part 2 https://youtu.be/ecz93B5SRsQ - How to test an electronic EGR valve (GM P1406 case study) https://youtu.be/te_kapz-fj4 Playlist: - (Chapters 9, 10 and 11) The 5v Reference and Signal Circuit Quick Tests https://www.youtube.com/playlist?list=PLAFYVCyenqcpP9ykkWb2D16nVEjyQ1eTZ 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. 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 https://www.scannerdanner.com/join-scannerdanner-premium.html 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! Disclaimer: 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.