How to Use an OBD Scanner to Detect Mercedes Fault Codes in the UK

Table of contents

• What can an OBD scanner do?

• How to use an OBD scanner on your Mercedes

• Find the right OBD scanner for your Mercedes

• FAQs about OBD scanners

Do you own a newer Mercedes? Expect it to have infinitely more electronics and control units than a model built in the 1990s or earlier, which also means more possible points of failure. Thankfully, OBD scanners like iCarsoft can help you identify Mercedes fault codes quickly, so you don’t have to book a mechanic right away.

Learning how to use an OBD scanner such as the iCarsoft CR Pro+ can save you both time and money. Here’s a simple guide to help you understand how these tools work and how to use them properly.

What can an OBD scanner do?

Even if you’re using a standard OBD scanner, you should be able to:

• Read and clear generic powertrain and emissions fault codes

• Display freeze frame data

• Perform I/M readiness checks for MOT testing

• Show live vehicle parameters and sensor readings

However, basic scanners may not access manufacturer-specific systems, such as your car’s

body modules and comfort systems, or even network-related fault codes.

How to use an OBD scanner on your Mercedes

Menus and controls vary depending on the scanner model, but the overall process is very similar across most devices.

1. Connect the OBD scanner

Most newer Mercedes models have OBD2 ports. You’ll find this beneath the steering wheel or somewhere around the centre console area.

Some scanners connect with a cable, while newer models, such as the iCarsoft CR MAX BT, use Bluetooth connectivity instead. Are you using a wireless scanner? Make sure that the connection is properly paired before continuing.

2. Turn on the ignition

Switch on the ignition so that your vehicle’s systems become active before running diagnostics. Be sure to turn off any running electrical equipment, such as the headlights and radio, so you reduce power consumption while scanning.

Depending on your vehicle, you may be able to use iCarsoft for diagnostics while the engine is still running. Fault codes remain stored until manually cleared, so starting your engine can help your diagnostic tool check live sensor data and monitor readings in real time.

3. Select your vehicle

After successfully connecting iCarsoft to your vehicle, you’ll usually need to choose your Mercedes model and vehicle specifications. This information allows the diagnostic tool to communicate correctly with your vehicle’s control units and interpret the readings properly. Most modern scanners can already identify your vehicle by its VIN number. Otherwise, you can always enter your VIN manually to proceed with the scan.

4. Pick the control unit or fault scan

With most OBD Scanners, you can decide whether to scan a specific control unit or run a complete scan across the entire vehicle. If you’re not sure what to do, you can check your scanner’s built-in help section or user manual. A full scan should take anywhere from a few seconds to several minutes, depending on your Mercedes and the number of control units installed, a full scan can take anywhere from a few seconds to several minutes.

5. Go over the fault codes

Some codes immediately indicate a specific fault: C1020, for example, often relates to a wheel speed sensor problem, which can affect your ABS or traction control system. But other codes need more investigation. P0171 or P0174 usually means the engine is running too lean, but the cause could also be a vacuum leak or a fuel delivery problem. This is why it's important to treat codes as just your 'starting point' for diagnosing an issue.

Get the right OBD scanner for your Mercedes

At HIDS-Direct, you can browse a wide selection of iCarsoft OBD scanners to help you diagnose fault codes on your Mercedes diagnostics. Here, you can check out securely and track your delivery for a small fee. If you change your mind, you’ll have peace of mind knowing your order is backed by our 30-day hassle-free returns policy.

FAQs about OBD scanners

Where is the OBD2 port located?

In most OBD2-compliant vehicles, you should find the OBD2 port within about two feet of the steering wheel. It’s usually underneath the driver’s side dashboard, but it may be hidden behind a removable cover or positioned near the interior fuse box.

Can an iCarsoft scanner work with older Mercedes models?

It depends on the scanner you choose. The iCarsoft CR Pro+ Enhanced Version already includes a dedicated 38-pin Mercedes-Benz adapter.