Used Car Diagnostic Scan
Every modern car has dozens of control units that store fault codes. A computer diagnostic scan reads all of them, not only the engine, and shows problems the dashboard may not display. It is the quickest way to find an electronic or hidden fault in a used car, or to explain a warning light.
From AED 150Written quote after diagnosis, before work startsConvenience fee applicable · shown on your written quote
- 30-60 minutes
- Can be done at your location
- Convenience fee applicable · shown on your written quote
- Diagnosis free with repair
How we do used car diagnostic scan
- 1
Connect and identify the car
The scanner links to the car's diagnostic socket and reads the VIN and the list of modules it carries, so we know what should be present.
- 2
Read every module
Stored, pending and historical codes are recorded for each unit, along with the status of readiness monitors that show whether the emission tests have run.
- 3
Check live data
With the engine running, we compare sensor values such as coolant temperature, fuel trims and gear oil temperature against what we expect. Odd readings point to wear.
- 4
Explain the findings
Codes are translated into plain language, with which are minor and which deserve concern, and what further tests or repairs they point to.
Why scan a used car before buying
- A warning light on the dash that the seller says is nothing
- A used car whose lights all behave perfectly but whose history you cannot verify
- Gear changes, steering or braking feel that is not quite right
- Intermittent faults that disappear and return
- A car that has recently had its battery disconnected before viewing
- Mileage, service or airbag history you would like to cross-check
What usually causes it
Fault codes stored in many modules
Engine, gearbox, ABS, airbag, steering, climate and body modules each keep their own list. A fault in the airbag or ABS unit never shows on a simple engine-only reader.
Recently cleared faults
Sellers sometimes clear codes before a viewing. Readiness monitors that are incomplete, or counters showing few drive cycles since a reset, give the game away.
Failed sensors and actuators
A scan shows live values, so we can see a sensor reading that is out of range, or an actuator that does not respond when commanded.
Software and coding issues
Mismatched or missing coding, especially after parts have been swapped, can disable features or hint at undisclosed repairs.
By make and model
BMW
These cars keep detailed fault histories in many modules, so a full scan often reveals a stored transmission, steering or suspension fault long before the owner notices.
In Dubai, Sharjah and Ajman
Cars imported for the UAE market, and those sold on after years in the Gulf, often arrive with codes relating to heat-damaged sensors, tired batteries and AC systems. A scan shows which of those are old, cleared recently or still active, which is exactly what a buyer needs to know.
Questions about used car diagnostic scan
Is this the same as the free scan a parts store offers?
No. A basic reader only talks to the engine computer and shows a code number. Our scanner reads the other modules and live data, and we interpret them.
Can the scan miss a problem?
Yes. A scan cannot see worn mechanical parts that have not yet set a code. That is why it complements a physical inspection and does not replace it.
Does a clear scan mean the car is fine?
It is a good sign, but not a guarantee. Look at readiness monitors and the combined result with the physical checks before you decide.
Can you scan my own car if a light is on?
Yes. We read all modules at your location and tell you what the light means. If a repair is needed, diagnosis is free once you go ahead with the work.
Last updated
Get a written quote
Tell us about your car. You get an itemised quote before any work starts, and you choose OEM, aftermarket or used parts.