Car Diagnostics | Book a Car Diagnostic for your Subaru

Trustpilot rating for all RAC Mobile Mechanics.

Why choose the RAC for a car diagnostic?

With RAC Mobile Mechanics, you can avoid the hassle of taking your vehicle to a garage. They can do a vehicle diagnostic check on your driveway, so you don't even need to leave the house.

When it comes to diagnosing issues with your vehicle, our friendly expert mechanics are here to help. We use state-of-the-art diagnostic equipment to accurately identify any problems, ensuring your vehicle runs smoothly and safely. The price includes the diagnostic service – no hidden costs. Just friendly, honest experts.

Close up of an RAC Mobile Mechanic underneath a car

Our top pick for your Subaru

We’ll come to you at home or work

RAC Mobile Mechanic for your Subaru

At the RAC, we’ve got over 125 years’ experience in offering complete peace of mind to our members. We’re best known for our breakdown service. And now – our new RAC Mobile Mechanics are here to help make every day motoring easier. If you need a service or repair, they’ll come to you at your home or work.

Book a car diagnostic

For a limited time, get £50 off repairs over £150 when you book a diagnostic test. Offer ends 09/12/25, 09:00.^**
Our mobile mechanics will spend up to 30 minutes checking your car for faults and talk you through any repairs you might need and give you a report for your records.

OEM quality parts

We use original equipment manufacturer (OEM) standard parts, which means every new part will be the same standard and same quality as the original part it replaced.

Mechanics you can trust

Our mobile mechanics are friendly, honest, and backed by the RAC.

Close up of an RAC Mobile Mechanic running a vehicle diagnostic check

Book a repair

It’s easy to book a car repair online. We bring the garage to you with RAC Mobile Mechanics, or find a trusted local garage. Common repair jobs include:

Clutch Replacement

We diagnose and repair clutch issues – whether your clutch is heavy or slipping, or you’re having trouble changing gears.

Alternator repair

We check and correct alternator faults to keep your charging system running smoothly.

Oil change

Oil is vital to a healthy engine, so it’s important to change it regularly.

Brake pads & Discs

If your brakes are making noise or you’re noticing reduced stopping power, it’s likely time to replace your brake pads or discs.

And it’s not just car diagnostics that we do for your Subaru

Mobile mechanics bring the garage to you, saving you the hassle of getting your car to a garage. If you need a service or repair, they’ll come to you at your home or work.

A close up of an RAC mobile mechanic looking under the hood of a car

Try one of our RAC Approved Garages

View all garages

Portside Cars LTD

4.0/5

We are a family run business and it is important to us that your trust us and feel comfortable with us. We pride ourselves on giving the best and honest service that we possibly can with the quickest turnaround time.

Unit 8, Canal Bridge Enterprise Centre, Meadow Lane, Ellesmere Port, CH654EH

Service Garage MOT & Repair Centre

5.0/5

Service Garage has been trading for over 60 years, established in 1946 we provide an extensive range of motoring services for Southend-on-Sea and surrounding areas. We can offer free collection and delivery service. The services we provide include; MOT testing, servicing, repair, batteries, tyres, exhausts, punctures, air conditioning and diagnostic testing.

4 Towerfield Close, Shoeburyness, Southend-On-Sea, SS3 9QP

A1 Tyres and Exhausts

5.0/5

With over 30 years experience of automotive repairs in Coventry, A1 Tyres and Exhausts is a name that you can rely on to deliver a professional, high quality, and reliable service, that will meet all of your car needs. And above all, we are a name you can trust again and again.

Unit 12-13, Relton Mews, Coventry, CV65HE

Richardsons Colchester

4.8/5

Established in 1966 we are one of the South East's leading vehicle repair centres. We have a team of highly trained ATA staff and we are a BSI approved repair centre so you can ensure your vehicle is repaired correctly. We carry our vehicle servicing and repairs at very competitive prices but still follow the exact schedule recommended by the manufacturer and your warranty is NOT compromised regardless of the age of the vehicle. We also fit parking sensors, tyres, batteries, in fact we can undertake almost any of your car needs. We have alos recently been certified as a Which Trusted Trader which the company has been audited on our ability to provide customers with a honest service quality and cost standard. See for yourself by visiting www.grahamrichardsons.co.uk

Grange Way, Colchester, CO28HG

LM Motor Clinic - Kilbirnie

5.0/5

With over 20 years motor trade experience, 2020 saw the establishment of LM Motor Clinic. A business driven by customer service. The ethos at the heart of LM Motor Clinic was to deliver an excellent customer service experience to all customers. We are North Ayrshires only Rac approved Garage. We are also Ayrshires only Castrol service we ensure we use the correct oil for your vehicle. Call us today to book your next service.

30 Holmhead, Kilbirnie, KA256BP

Frequently asked questions on car diagnostics

How much does it cost to diagnose a car problem?

The cost you pay can vary depending on the type of car and how complicated the diagnostic test. Check with your mechanic for a quote.

Is a car diagnostic test worth it?

Yes, a diagnostic test may save you a lot of money. It finds issues early before they become costly repairs. It can also keep your vehicle running efficiently and safely

Can I do a car diagnostic myself?

While you can buy a diagnostic tool, interpreting the results needs expertise. It’s best if you to have a professional mechanic perform the test.

How long does a car diagnostic test take?

Diagnostic tests take from 30 minutes to a few hours. This depends on what issues are being looked at.

What are common car diagnostic codes?

Common diagnostic trouble codes include:

P0300: Random/Multiple Cylinder Misfire Detected
P0420: Catalyst System Efficiency Below Threshold
P0171: System Too Lean (Bank 1)

These are general examples, so your car may have different codes. Always check with a mechanic so you get an accurate diagnosis.

Is a car diagnostic test necessary for a service?

Yes, they are. Regular diagnostics can help keep your car in good health. It makes sure that underlying issues are addressed quickly, so you can drive with peace of mind on the road.

Again, keep in mind that mechanics might have their own checklists. Chat with your mechanic to be sure that they address any specific issues you have.