It starts from nothing on every job, it forgets what you ruled out an hour ago, and it can't be handed to anyone.
DAVO is where it lives instead. Not a scan tool, and not a replacement for one: it sits alongside whatever you already use and holds the reasoning while you work. Every failure mode for the system in front of you, authored by people who have seen it fail, ordered so you test what eliminates the most.
The call all garages dread.
The car is back, the customer is calmer than you would like, and the invoice for the part you fitted last week is sitting on the counter. Somebody has to explain what the four hours they paid for last week actually bought them.
Warning lights, fault codes, symptoms, complaints. All of it arrives at once and none of it is an answer. They are simply clues to the root cause.
One client complaint can support many possible explanations. Every one of them is plausible. None of them is proven. That’s the job of the technician.
Time is limited, costs add up, and the customer expects an answer today. The pressure often causes the decision to get made before the evidence has been gathered.
One hypothesis starts to feel more convincing than the others. It is usually the one you have seen before. Or mentioned in a TSB. Your view narrows even before the testing starts.
Stop guessing. Write the observation on a note and put it where you can see it. The first step toward certainty is analysing the data and not choosing an early answer.
Hypotheses fan out across the top. Under each hypothesis sit its own candidates, and under each candidate its own diagnostic tests, descending downward. A column is one possibility with its own descent, not a stage that everything passes through.
This is how it looks in real life. Messy. Worked. Honest. We ran this system for years on unfixable problems and on diagnostic training courses.
The case remembers the current stage the diagnosis has got to. What is open, what has been tested, what still needs evidence. Nobody has to reconstruct it again after a coffee break or interruption.
Run a test that refutes a hypothesis and the whole branch comes off the board: the hypothesis, its candidates and its tests, together. Diagnostics – proving what is NOT the problem item. One result clears an entire region of possibility. Repeating this process removes possibilities until only the root cause remains.
The notes flatten into tiles. No colour translation. Only the geometry changes. Same colours, same meaning, new representation.
Not a fault code database. Not a flowchart. Not a TSB database.
Every failure mode for that system is already written down, by people who have seen it fail. The technician describes the symptom and the possibilities come back ranked, all of them, not the ones they happened to remember. They choose which to pursue, work down to a specific test, and take the reading. The hypothesis survives or it is eliminated.
It only catches the faults its author thought of. The one in your bay is rarely on that list. DAVO lets you keep the judgement open and remembers your reasoning.
of eliminations captured as you make them.
Every test you ran, what you expected, what you read, and what it ruled out. Written while you worked, not reconstructed at the counter.
But usually none of it gets written down. Four hours of ‘time spent’ shows as four hours of nothing to show for it.
Anyone can say they checked it. You can show which tests said so.
Get one wrong and the reading cannot be compared to anything. Most bad diagnoses are not bad reasoning. They are a good reading taken under the wrong conditions, compared against a value that assumed different ones.
Every test carries its own criteria, authored for that component, in the right state, at the right point, with the right tool. Nothing is inherited from a general case.
This method did not come out of a workshop and go straight onto a website. It went into skills competition first.
Technician DM, competing for Team UK.
Technician ES scored 528 in Automobile Technology.
The UK's most contested individual award for working technicians, and the method has been in the room for over a decade of them.
Competition is the hardest test a diagnostic process can face. Competitors are watched, timed, and rated on every individual step. There is nowhere to hide a lucky guess and no credit for arriving at the right answer by the wrong route. The judges are scoring the reasoning, not the result.
That is the same thing DAVO scores. If the method holds up under a stopwatch in front of international judges, it will hold up on a Tuesday morning with three cars in and one technician off sick.
It is also how the best technicians in the country were taught to think. That is the company this puts you in.
Top Technician is judged over multiple rounds against working technicians from across the UK, on real vehicles, under time. Eleven consecutive years of winners, runners-up, finalists and semi-finalists is not a fluke, and it is not one competitor having a good day.
You stop absorbing the cost of work nobody can account for, and you stop having the conversation where the honest answer is that you are not sure what went wrong.
You concentrate on the reasoning, and your eliminations are captured as you make them.
So the learning happens on the reasoning rather than on recall.
Compare it to a comeback rather than to a diagnostic.
A comeback costs you the labour twice, the part you already fitted, the slot in the diary you cannot now sell, and a customer who tells other people about it. The monthly subscription is great value by comparison.
No. It sits alongside whatever you already use. Your scan tool reads the vehicle; DAVO holds the reasoning about what the readings mean and what to do next.
A browser. It runs on the workshop PC, a tablet on the bench, or a phone. Nothing to install. The learning is done online, in your own time, with a call to get you started.
Per technician. Each person gets their own login, because the case history follows the person who worked it. Groups, networks, factors and colleges buy blocks of seats and allocate them, which is a different conversation: six different reasons to pay for it.
The first case. There is nothing to install, no configuration and no data to import. What takes the effort is the method, so every licence includes an onboarding call, the e-learning, and regular remote workshops.
People who have seen the failure modes and flowcharts fail. It is authored by experienced subject matter experts.
The quickest way to judge this is to watch it work on a fault you recognise.
