Fault Code Diagnostic Aids

truck wiring diagrams mitchell 1Sometimes diagnosing a fault code can be a challenge. With ECMs, wiring diagrams, charts, specifications, component locations, and connector and component tests, it can really get confusing. In the early days, prior to all the electronic components in trucks, it was pretty easy to spot a problem with your eyes alone.

Today, the ballgame has changed. Electronic components can be deceiving and make you think everything looks good, and you end up asking yourself, “So where’s the problem?” Understanding how a circuit works will help you with a quick and accurate diagnosis and hopefully prevent changing out perfectly good parts.

When diagnosing a fault code, the best place to start is the “Circuit Description” section in the TruckSeries truck repair software.  The information provided here gives you a description of the circuits involved, applicable sensors and components, specifications and how the circuit works.  Reading this section along with viewing the wiring diagram for the applicable components will put you ahead of the game.

Wiring diagrams make it easy to see the path of a circuit. Now you have a basic understanding of how everything is supposed to work and a logical path to follow.  Save yourself some time and frustration and take advantage of the information TruckSeries provides.

DTC P0101 repair information

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About the Author

Bruce Cansler

Bruce Cansler started his automotive career in 1973 as a technician for Datsun. He retired from the U.S. Navy as a Seabee Construction Mechanic with 20 active years of service and 10 as a reservist, then spent time working in Ford, Lexus and Caterpillar dealerships. Bruce has obtained ASE certifications in both cars and medium/heavy trucks and has worked with the Commercial Vehicle Group at Mitchell 1 since 2009.