B 1.0
DX
Diagnosis
Finding out what is actually wrong is its own job, with its own price and its own product: a written finding naming the fault, the evidence and the operation that corrects it.
Reading a code takes ninety seconds and a parts store will do it for free. That is not diagnosis, and treating it as diagnosis is the most expensive habit in car ownership.
A stored code names a circuit or a cylinder that reported a problem. It does not name the component that failed. P0301 means cylinder 1 is misfiring; the cause could be the coil, the plug, an injector, a vacuum leak or low compression, and those are five different repairs at five different prices. Replacing the part a code sounds like is how people spend four hundred dollars and still have the fault.
Diagnosis is the work between the code and the answer: live data, freeze-frame, wiring checks, mechanical testing, and a technician who has seen the pattern before. It is skilled labour with real equipment behind it.
What you own at the end is a written finding. If you authorize the repair with us the diagnostic fee comes off it in full. If you decide to have the work done elsewhere, take the finding with you — you paid for it, it is yours, and we would rather you used it than guessed.
A steady light means get it looked at. A flashing light usually means a misfire severe enough to damage the catalytic converter, which turns a $200 repair into a $1,500 one in a matter of miles. Stop driving and telephone.
Tell us these at write-up
- The symptom, in your words
- When it happens, how long it has been going on, and whether it changes with speed, temperature, braking or turning. Do not translate it into car vocabulary — the raw description is more useful.
- Whether a light is on
- A stored code, a flashing light and no light at all are three different starting points. A flashing check engine light means stop driving.
- What has already been done
- Parts already replaced, codes already read, and any estimate you are holding from somewhere else. It saves you paying to rule out the same things twice.
- Whether it is intermittent
- A fault that happens once a week is a different job from one that happens every time, and it may need the car for longer.
- How you want to be reached
- Diagnosis ends in a telephone call asking you to authorize or decline a repair, and that call is easier if we have the right number.
All of it goes on the repair order in your words, and the written estimate is built from it. See estimate and authorization.
- Estimate
- Written, against your vehicle
- Authorize
- By you, before work starts
- Changes
- A revised number needs a second authorization
- Old parts
- Returned if you ask at write-up
Diagnosis is $149, and it is credited in full against the repair it identifies if you authorize that repair with us.
B 1.1 Prices
What these operations cost
Published ranges for the operations in this group, at a labor rate of $149 per hour. Everything on one page is on the pricing page.
| Operation | Time | Price |
|---|---|---|
| Diagnostic, standardCodes, live data, freeze-frame, targeted testing | 1.0 hr | $149 |
| Extended electrical diagnosisWiring, grounds, parasitic draw, network faults | 2.0–3.0 hr | $298–$447 |
| Intermittent fault diagnosisMay require the vehicle for more than one day | from 2.0 hr | from $298 |
| A/C performance testPressures, temperatures, controls | 0.8 hr | $129 |
| Charging and starting system testBattery, alternator, starter draw | 0.6 hr | $89 |
| Brake inspectionMeasured pad and rotor thickness, written | 0.5 hr | $69 |
| Pre-purchase inspectionWritten report before you buy a used car | 1.5 hr | $189 |
| Second-opinion estimate reviewWe read someone else’s estimate against the car | 0.7 hr | $99 |
Prices are USD ranges for the operation named, at a labor rate of $149 per hour, and include parts and labor unless a line says otherwise. They exclude shop supplies, disposal fees and tax. They are published so you can budget before you call, and they are not an estimate for your vehicle. Reviewed September 2026. The estimate for a specific vehicle is written against that vehicle and authorized by you before any work starts. See the disclaimer.
Questions Diagnosis
Questions about this work
Specific to this group. The general ones — estimates, warranty, payment, shuttle — are on the FAQ page.
Why is diagnosis not free?
Because it is not a ninety-second code read, it is an hour or more of skilled labour with equipment behind it. A shop that gives it away has to recover the cost somewhere, and the usual places are the parts markup or a recommendation you did not need. We would rather charge for the work and let you see what it cost. It also comes off the repair if you authorize it here, so in the ordinary case you never pay for it twice.
Can I just have the code read?
Yes, and we will tell you what the code is free of charge if you stop by. But we will also tell you plainly that the code is not the answer, and we will not recommend a repair off the back of one, because doing that is how people replace the wrong part. Several parts stores will read codes too. Use that to decide whether to book diagnosis, not to decide what to buy.
What if you cannot find the fault?
It happens, particularly with intermittent faults that will not present while we have the car. In that case you are told exactly what was tested and ruled out, in writing, and what would be needed to go further. You are not charged again to continue from where we stopped. What we will not do is guess at a part and charge you for fitting it.
I have an estimate from another shop. Will you look at it?
Yes, and that is a real service rather than a courtesy — it takes a technician and the car. We read the estimate against the vehicle and tell you whether the operations listed are consistent with what the car actually needs. Sometimes the answer is that the other estimate is entirely fair, and we will say so.
B 0.0 The rest
Everything else we do
The system you notice only when it is wrong. Pads and rotors, brake fluid, calipers and lines, tires, balancing and four-wheel alignment.
In this city the air conditioning is not a comfort item and the cooling system is not a seasonal one. Performance testing, leak finding, compressors, radiators and water pumps.
Misfires, timing components, belts, starters and alternators, transmission service, axles and driveline — the work that follows a diagnosis rather than preceding it.
Oil and filter, fluids, filters, belts, plugs and the mileage-interval services, each priced as a line item rather than discovered at the counter.
Describe it and we will name the operation
You do not need the right word for it. Tell us what it does, when it does it, and how long it has been doing it, and we will tell you what it probably is and what that costs.
Arlington Motor Company, Inc. · 10939 Atlantic Blvd, Jacksonville, FL 32225