If you’re tired of paying $150 or more just to clear a fault code, you’re not alone. Many diesel truck owners and fleet operators are ditching the dealership and taking diagnostics into their own hands. With the right tools, clearing fault codes is fast, easy, and doesn’t require a service appointment or tow.

Here’s how you can clear codes like a pro — without the dealer.

What You Need

To clear fault codes yourself, you’ll need:

• Diesel diagnostic laptop kit (like the ones from NoFeeDiesel)
• RP1210 adapter (e.g., Nexiq USB-Link or Cummins Inline 6)
• OEM-level software (Detroit DDDL, Cummins Insite, etc.)
• A running or key-on truck

What Are Fault Codes?

Fault codes (DTCs) are alerts from your truck’s electronic control modules (ECMs). They tell you when something is wrong — or when the system thinks something is wrong.

Common causes:

• Sensor failures
• Temporary voltage drops
• Clogged DPF
• Fuel system fluctuations

Sometimes the issue is minor or already fixed, but the code stays active until it’s cleared.

 Step-by-Step: Clearing Fault Codes

1. Connect your RP1210 adapter to the truck’s 9-pin port
2. Launch your diesel diagnostic software
3. Connect to the ECM
4. Navigate to the Fault Codes or Active/Inactive Codes section
5. Click “Clear Codes” or “Reset Faults”
6. Cycle the ignition to complete the reset

In most cases, inactive codes can be cleared right away. Active codes may require you to fix the issue or complete a regen before clearing.

Pro Tips

• Clear codes only after verifying the issue is fixed
  Don’t just wipe them blindly — especially if you’re dealing with aftertreatment (DPF/DEF) systems.
• Run a regen before clearing emissions codes
  Most emissions-related codes (especially on Freightliner or Peterbilt) require a successful regen before the code will disappear.
• Use the right software
  Make sure your software matches your engine: Cummins = Insite, Detroit = DDDL, Paccar = Davie4, etc.

Why It Pays to Do It Yourself

Let’s break it down:

Task	Dealer Cost	DIY with Diesel Laptop
Fault code scan	$150+	Free after setup
Forced regen	$300–500	Included
Parameter tweak	$250+	Included

After just 1 or 2 uses, your diesel diagnostic laptop pays for itself.

Ready to Take Control?

At NoFeeDiesel.com, we make it easy:

 

• Laptops preloaded with dealer-level software
• Plug-and-play kits — no subscriptions
• 30-day money-back guarantee

Don’t let a fault code cost you time and money. Get your own scanner and handle it yourself.

👉 Shop Diesel Laptops Now