Understanding DTCs in Your Car’s OBD System

🚗 What Are DTCs in OBD Systems? A Simple Guide to Fault Codes

Modern cars are smart – they don’t just drive, they communicate. But when something goes wrong, that dreaded check engine light appears. What it’s actually doing is alerting you to a DTC, or Diagnostic Trouble Code, stored in your vehicle’s OBD system.

At Car Keys in London, we help drivers not only read these codes but also understand and clear them – saving you time, money, and unnecessary stress.

🔍 What Is a DTC?

DTC stands for Diagnostic Trouble Code. These are specific codes stored in your car's computer system (ECU) when it detects a problem in one of its systems – like the engine, transmission, exhaust, fuel system, or electronics.

Each code is like a message from your car saying:“Something’s not right – here’s what I found.”

These codes are accessed through the OBD (On-Board Diagnostics) system, which is built into all cars manufactured from 1996 onwards.

🧰 Common Reasons You Might See a DTC:

• Faulty oxygen sensor

• Loose fuel cap

• Engine misfires

• ABS or airbag faults

• Emissions issues

• Battery or charging system problems

📟 How Do We Read and Clear DTCs?

Using professional diagnostic tools, we connect to your car’s OBD port (usually under the dashboard). Within seconds, we can:

• Read current and stored DTCs

• Explain what each code means in simple terms

• Identify whether it's a serious issue or a minor glitch

• Clear the codes (after fixing the issue, or if it's a false alert)

• Reset your check engine or warning lights

We offer this as part of our mobile service across London and the M25, meaning we come to you – whether you’re at home, at work, or stranded on the roadside.

⚠️ Why You Shouldn’t Ignore DTCs

Some DTCs are minor and don’t affect the car’s performance. Others can point to serious problems that, if left unresolved, can lead to costly repairs or even breakdowns.

Ignoring these codes can also cause your vehicle to fail MOT due to active warning lights or emissions faults.

✅ Need a DTC Scan or Reset?

If you’ve got a check engine light or any warning on your dashboard, don’t guess – let us diagnose it properly.

📞 Call or WhatsApp us at 07577 937421 or book at www.carkeysinlondon.co.uk📍 We cover all of London + M25 area💼 Fast, affordable, and fully mobile

Let your car talk – we’ll translate.