Auto Repair and Diagnostic Time

As a veteran auto mechanic, I will be the first to defend charging for diagnostic time. Today’s cars demand an in-depth understanding of a vast array of electronics, computers, processors – having this knowledge is valuable. However, too often, diagnostic time is billed arbitrarily and/or excessively.

A common example of excessive diagnostic charges is checking for a leak. Whether it’s coolant, oil, or transmission fluid, too often 1.0 labor hour is billed for inspections (which often consist merely of a glance at the under-carriage) that should bill only .3 hours.

Another frequent scenario is the 1.0 hour of labor that’s charged to investigate a check engine light. Essentially the technician plugs in a scanner that communicates with your vehicle’s on-board computer and reads a trouble code. Depending on the vehicle, this service bills from .2 to .5 hours. The trouble is that the bulk of repair shops charge 1.0 hour to do this.

Charging 1 hour "just" to pull a fault code is excessive. Charging 1 hour to "diagnose" a check engine light is a different story. The code that’s pulled from your computer is only a starting point. The technician must then follow the appropriate diagnostic path to uncover why the code set in the first place. This process may take the technician 30 seconds or it may require hours.

Simple answers to all your car's warning lights

Is it fair to pay 1 hour of labor for a 30-second diagnosis? If the diagnosis is accurate and the labor time corresponds with manufacturer guides and industry standards, then yes. You are paying for experience.

Importantly, claims of experience do often get abused or applied arbitrarily, but so we understand both sides of the situation, here’s an example to put diagnostic charges in context.

A friend called whose vehicle kept stalling and then intermittently wouldn’t start. Knowing the common problems associated with his particular model, I was able to make an accurate diagnosis over the phone. What was that worth? For his particular model it was worth $150 in diagnostic time.

---

---

In the end, paying for diagnostic time is routine. It’s part of the process of repairing your car. That said, don’t be afraid to ask your repair shop to justify their diagnostic time. Make sure you get a complete and detailed description of the diagnostic process that accounts for the charges. If the diagnostics charges seem excessive and/or evasive, get a second opinion.