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Lori Sullivan

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Jul 20, 2016

1 minute read

Fleet Management Blog

12 Diagnostic Tests You Should Be Using

As we discussed in 3 Ways Diagnostics Improve PM Efficiency, performing vehicle diagnostic tests as a part of a PM program can help detect issues early on, thus reducing maintenance time and costs.

fuel system test

In addition to the tools needed for diagnostic testing, it is important to understand some of the common diagnostic tests performed and the value behind each.

Here are 12 common vehicle diagnostic tests:

  1. Battery check - Ensure full or acceptable voltage and amperage capacity.

  2. Starter draw test - At operating temperatures, the starter should not take too much amperage out of the battery, causing premature failure.

  3. Voltage drop test - There should be no excessive resistance in the starting circuit to cause high temperatures; no broken circuits.

  4. Charging system - Will the alternator supply the rated voltage and amperage to the battery?

  5. Pressure test - Pressure test the cooling system and check hoses, coolant, antifreeze and all belts.

  6. Primary ignition check - Test the points and condensor.

  7. Secondary ignition check - Test the coil, plugs, high-voltage wires and distributor cap.

  8. Ignition timing test

  9. Cylinder balance and compression check

  10. Emission control - Test for proper tolerances.

  11. Exhaust system check

  12. Fuel system check

To learn more about vehicle diagnostics…

Check out 3 Ways Diagnostics Can Improve PM Efficiency and 8 Diagnostic Must-Haves for PM Inspections!

Sources: Fleet Management, 11th Edition by John Dolce

About the Author

Lori Sullivan

Lori Sullivan

Marketing Director

Lori is the Director of Marketing at Fleetio and a seasoned B2B marketing and automotive advertising expert. When she's not nerding out on marketing metrics or podcasts, she is binge-watching Netflix crime dramas with her dog, Fitzgerald.

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