Most trainers say what makes for a great diagnostic technician is not knowing everything but knowing what they don’t know. Some say they have an internal diagnostic strategy that finds problems with the vehicle and the fault with their thinking.
A great technician knows the most potent phrase in automotive diagnostics language is: “I don’t know.” It can be hard to say, but it’s a start on a journey usually ending in a correct diagnosis. Sometimes confidence and ignorance prevent technicians from seeing their diagnostic blind spot.
I recently read about the phycological phenomenon called the Dunning-Kruger Effect. Social psychologists, David Dunning and Justin Kruger, proved some incompetent people lack the ability to accurately estimate their own competency. It’s like your friend who thinks he is Mario Andretti, but no one wants to ride with them.
To prove their theory, Dunning and Kruger took a group of students and made them take the same exam. After the exam, they asked the students how they thought they did. They found students with the worst scores thought they did the best. Students who scored highest often underestimated their performance.
The researchers realized that some students had “cognitive bias” that made them think they were falsely superior. Dunning and Kruger realized the low scoring students were not narcissistic but lacked the knowledge and cognitive ability to evaluate their own incompetence.
We often see the Dunning-Kruger Effect in the actions of some technicians. They have this ingrained cognitive bias that any vehicle problem can be solved by swapping parts. These technicians are ordering parts while the other guy is looking at a wiring diagram. They think a parts swap for a diagnosis is far more effective than testing and finding the root cause before calling the customer. They never verify a repair or a test if a critical and related monitor can be completed.
Most of all, the Dunning-Kruger technicians are blind to the cost of a comeback. They don’t see the damage they are causing to everyone’s reputation by unnecessarily replacing parts.
However, “I don’t know,” is going to have to become a more common phrase as new technologies like ADAS, advance direct injection and telematics start to find their way to your bays. A lot of these technologies will require service with sophisticated tools and training. Knowing what you don’t know will often be the first step. iC
