Car diagnostics at the Ariol Auto workshop: we read fault codes from the control units, analyse sensor data, inspect the components and look for the cause of the fault. We only start a repair once you have approved the estimate.
Priisle tee 18, Tallinn
Mon–Fri: 09:00–18:00
Cars and minibuses of all makes
What we check during car diagnostics
Computer diagnostics shows which fault codes the control units have stored and how the sensors are working. Checks and measurements then help to narrow down the cause. What we check depends on the problem and on the vehicle. If you need a full diagnosis of the car, the systems listed below can be checked in a single visit.
ECU fault codes
We connect to the diagnostic port and read fault codes from the control units for the engine, gearbox, ABS, airbags and any other systems available on the specific vehicle.
Sensor data
We look at live data: temperature, engine speed, load, and readings from sensors and actuators. This shows what is happening with the vehicle at the moment the fault appears.
Electrics
We check the battery, charging, starting, and the power and earth circuits. If the cause lies in the electrics, we carry out car electrical repair.
Engine and fuel system
We assess how the engine runs, including by ear, look for leaks, and check the level and condition of the fluids. We put faults right as part of engine and fuel system repair.
Transmission and drivetrain
We read automatic gearbox fault codes and check the drivetrain for noise and play, as well as the condition of the oil seals and bearings. We also repair manual gearboxes in our own workshop: manual transmission repair.
Chassis and brakes
With the car on a lift, we inspect the suspension, steering and brake system for wear, play and leaks. No scanner can show you this.
When your car needs diagnostics
Book a diagnostic check if you notice any of the signs below. The sooner the cause is found, the lower the risk that the fault will affect other components.
The Check Engine light is on. The engine control unit has detected a fault. The cause needs to be found, even if the car drives as normal.
The ABS, ESP or airbag warning light is on. The safety system may be working with limitations or may be switched off.
The engine is hard to start or runs unevenly. It misfires, stalls or the idle speed fluctuates.
The car has lost power. It accelerates poorly or has gone into limp mode.
Fuel consumption has gone up. For no obvious reason and with no change in your driving style.
The battery keeps going flat. The car will not start after standing, or the electrics play up. If the battery has reached the end of its life, a battery replacement will help.
You notice noises, vibration or pulling. Knocking from the suspension, humming, a vibrating steering wheel or the car pulling to one side.
You are buying a car or have had a collision. Before you buy a used car, and after an accident, some faults cannot be seen from the outside.
How car diagnostics works
First we clarify what is happening with the vehicle, then we look for the cause, and only then do we agree the repair.
Symptoms
We ask when the fault first appeared, under what conditions it shows up and which warning lights are on the dashboard.
Codes and data
We connect the diagnostic equipment and read the fault codes and the systems’ operating parameters.
Finding the cause
We check the components that the fault codes and symptoms point to: inspection, measurements and function tests.
Estimate and repair
We explain what we have found and what is urgent. We carry out the repair once the estimate is approved, then check the result.
A fault code is not yet a diagnosis
A fault code shows in which system, and under what conditions, the control unit detected a deviation. The same code can have different causes. For example, a “lean mixture” code can be triggered by an air leak, a faulty mass air flow sensor, low fuel pressure or a dirty injector.
That is why a fault code is our starting point, not a reason to replace a part. After reading the codes, we:
- look at the conditions under which the code was stored;
- compare the sensor readings with the specified values;
- check the wiring, the connectors and the component itself;
- clear the codes after the repair, not instead of it.
When not to keep driving
Stop in a safe place and do not continue your journey if:
- the Check Engine light is flashing — a sign of severe misfiring;
- the red oil pressure warning light is on;
- the engine is overheating;
- braking or steering has become noticeably worse.
If the Check Engine light stays on but the car behaves as normal, you can drive carefully to the workshop. However, do not put off the diagnostics.
Pre-purchase car inspection
The seller may not know about faults or may keep quiet about them. Before you buy a used car, we check:
- the control unit fault codes;
- how the engine and gearbox work;
- the suspension, steering and brakes, on a lift;
- for leaks, and the level and condition of the oil and other fluids;
- for visible damage and worn parts.
Arrange it with the seller in advance and book a time that suits you. The results will help you decide whether the car is worth buying and what repairs it will need.
Frequently asked questions about car diagnostics
How much does car diagnostics cost?
Diagnostics is charged by time, at the hourly rate in our price list. Current prices are on the Prices page. The total depends on the fault and on how many systems need to be checked.
How long does diagnostics take?
It depends on the fault. Reading the codes and checking the main parameters takes less time than tracking down an intermittent fault or an electrical problem.
What does a full car diagnosis include?
A full diagnosis is a check of all the main systems in one visit: we read the control unit fault codes and sensor data and check the electrics, engine and fuel system, transmission, and the chassis and brakes on a lift. Afterwards we explain what we found and agree the estimate with you.
Do you check the suspension and chassis?
Yes, on a lift: we inspect the suspension, steering and brakes for worn parts, play and leaks. Computer diagnostics cannot help here, as a scanner does not see wear in the chassis.
The Check Engine light is on — can I keep driving?
If the light stays on and the car behaves as normal, you can drive carefully to the workshop. If the light is flashing, the red oil pressure light is on, the engine is overheating or braking has got worse, stop in a safe place and do not drive any further.
Can you just clear the fault code?
We can, but if the cause has not been fixed, the code will come back. Clearing the codes also resets the systems’ readiness monitors, and this shows up the next time the car is scanned. That is why we look for the cause first and clear the codes after the repair.
Can you check a car before I buy it?
Yes. We agree the scope of the check with you in advance. Arrange it with the seller in advance and book a time that suits you.
Which vehicles do you work on?
Cars and minibuses of all makes. Our main focus is Citroën, Peugeot, Renault, Dacia, Ford and Volvo.
How do I book diagnostics?
Fill in the form on this page or call +372 5552 7985. Give your registration number or VIN and describe the symptoms: what is happening and which warning lights are on.
Book car diagnostics
Fill in the short form below — we will find a time that suits you.
Arrange a service visit today
Enter your vehicle details and a convenient time — we will contact you and confirm your booking.