Car Diagnostics | Book a Car Diagnostic for your Mercedes

Trustpilot rating for all RAC Mobile Mechanics.

Why choose the RAC for a car diagnostic?

At the RAC, we've got over 125 years' experience helping UK drivers. We have the skills and knowledge to keep your vehicle running.

Plus, with RAC Mobile Mechanics, you can avoid the hassle of taking your vehicle to a garage when you need a repair. We’ll come to you, at your home or work.

Close up of an RAC Mobile Mechanic underneath a car

Our top pick for your Mercedes

Our top pick

RAC Mobile Mechanic for your Mercedes

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.

A customer tending to her garage with an RAC Mobile Mechanic in the background

Book a car diagnostic

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. There are various ways we can check for faults, which could include plugging in to check your car’s onboard engine management system.

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 Mercedes

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

PJ Automotive Ltd

4.8/5

We are an RAC Approved Garage carrying out work on all types of vehicles including commercial vehicles to 5 ton. We can MOT class 4, 5 and 7 vehicles. We specialise in German brand vehicles (BMW, Mini, Audi, Mercedes). We can however carry out work on any make.

Mount Pleasant, Hanley, Stoke On Trent, ST14AY

Lushington Motors Ltd

4.8/5

Lushington Motors are an established local independent family run garage and are proud to be members of the LKQ-ECP 1 Tec Network. For your added peace of mind, we are members of the Motor Ombudsman service which is approved by The Trading Standards Institute. We are also members of the Independant Garage Association (IGA) and Trust My Garage network. In short, we are a local garage you can trust offering you the support and service guarantees of a national network, giving you complete peace of mind. We cover Hailsham, Polegate and surrounding Eastbourne area. We will only supply and fit quality O.E parts, so parts with the same quality, that were originally fitted to your vehicle at the factory. For added piece of mind we only use Shell engine oil.

Unit 10 Westham Business Park, Eastbourne Road, Westham, BN24 5NP

Auto-Line MOT Centre

5.0/5

Here at Auto-Line M O T we offer high quality servicing and mechanical repairs. We carry out any repairs to industry standard service manual labor times. We also offer a free collection and delivery service and vehicle movement services, which are subject to availability. We are a small close-knit team of two technicians with over 30 years of experience between us. We have a real passion for what we do and carry out every single job, no matter how big or small, to the highest standards. Owner Oliver is fully licensed, insured and qualified in the following; DVSA registered Authorised Examiner and mot tester Automotive Refrigerant Handling (EC Level 3 Award (IMI Awards Ltd) Light Vehicle Maintenance and Repair Competence, Level 3 Diploma (IMI Awards Ltd) Light Vehicle Maintenance and Repair Principles, Level 2 Diploma (IMI Awards Ltd). Numerous product courses with Ford Numerous product course with jaguar land rover Numerous product courses with BMW Luke is a landrover master technician Very experienced with all makes and models as comes from and aftermarket background. Light Vehicle Maintenance and Repair Competence, Level 3 Diploma (IMI Awards Ltd)

Unit 17 British Waterways Yard, Shardlow, Derby, DE722HL

Darlington Mot Centre

4.9/5

Darlington Mot Centre Mot cars, vans , motor homes , motorbikes , trikes ,quads • Comfortable reception to wait in • Motorcycle class 1 and 2 only £25 • Class 4 cars and vans only £45 • Class 7 & motor homes up to 3.5ton only £50 • MOT's carried out up to 28 days before expiry - keep your original expiry date • Post card reminder service so you never forget your MOT again • Free re-test within 10 working days • No charge for head light adjustments We service and repair all makes of vehicles All makes serviced and repaired • Full and Interim service • Body shop repairs for those little scrapes, dings and re-sprays • Air-con new and old gasses repairs • Timing belts and engine repairs • Brake disks and pads • Exhaust and suspension • Tracking 4 wheel alignment • Tyres new and part worn • Batteries, starters and alternators • Diagnostics and engine management systems • Clutches and gear boxes

Darlington Mot Centre, 410 Whessoe Road, Darlington, DL3 0RP

Prestige German Cars - Independent German Car Specialist

4.2/5

BMW | Mercedes Benz | MINI | Volkswagen | Audi | Skoda | SEAT | Smart Welcome to Prestige German Cars, established in 2003 and located in the North East of England. Boasting a purpose built 8 bay workshop, we offer everything a main dealer can at reduced prices. It is a point of pride for us to have the latest BMW & VAG dealer diagnostics and more, plus the equipment required to carry out everything your vehicle requires, ensuring we are up to date with all the latest techniques and know-how. Of course other makes and models can be catered for too!!

11, Shaftesbury Ave, South Shields, NE349PH

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.