Adjusting engine parameters on a CAT diesel engine gives you full control over how your machine runs — from idle speed and torque limits to emission thresholds and shutdown timers.

With the right diagnostic tools, you can safely change these settings using a CAT Comm 3 adapter and a diagnostic laptop — no subscription or dealership access required.

Here’s what you need to know before making parameter changes, and how to do it right.

What Are Engine Parameters?

Parameters are adjustable settings inside the engine’s Electronic Control Module (ECM) that control how the engine behaves. These may include:

• Maximum or minimum engine speed

• Idle shutdown timing

• Fan control settings

• PTO (Power Take-Off) behavior

• Cruise control enable/disable

• Torque curves

• Emission control triggers

• Speed governors

Changing these settings can improve performance, increase efficiency, or help meet fleet and job site requirements.

Step-by-Step: How to Safely Change Parameters on CAT Diesel Engines

1. Connect Your Diagnostic Setup

• Plug your CAT Comm 3 adapter into the truck or equipment’s diagnostic port

• Connect the USB cable to your diagnostic laptop

• Make sure all driver software is installed and the connection is live

2. Launch Your Diagnostic Software

• Open the software provided in your NoFeeDiesel laptop kit

• Let the program load and detect the ECM

• Select the vehicle profile and load connected modules

3. Access the Parameters Section

• Locate the section labeled “Parameters,” “ECM Configuration,” or similar

• Browse through parameter categories (fuel system, engine control, idle settings, etc.)

4. Review Existing Values

• Before editing anything, document the current values

• Take screenshots or export settings to save a backup

• Double-check parameter descriptions for clarity and impact

5. Make Adjustments

• Click the parameter you wish to edit (e.g., change idle shutdown from 5 to 15 minutes)

• Input your new value

• Some settings may require password authorization or manufacturer access level

6. Apply & Save

• Click “Apply,” “Program,” or “Send to ECM” to save the changes

• Wait for the confirmation message

• Restart the engine or control module if prompted

7. Verify and Monitor

• Reopen the parameter list to confirm your new settings are stored

• Start the engine and monitor live data to confirm proper operation

• Run a quick test drive or system check depending on the setting changed

Examples of Parameters You Can Adjust:

• Raise or lower the speed governor

• Extend idle shutdown for cold climates or overnight use

• Modify torque limiter for specific job requirements

• Enable or disable cruise control

• Adjust engine fan behavior for better cooling efficiency

All of these options can be safely modified with the right tools — no dealer appointment needed.

Important Notes Before You Change Parameters:

• Always check local laws and emissions regulations before modifying any factory settings

• Changing parameters incorrectly can cause poor performance or fault codes

• If you're unsure about a setting, consult a technician or review official service documentation

Take Control — Without Subscriptions or Limits

NoFeeDiesel diagnostic kits include:

• Rugged diagnostic laptops preloaded with powerful ECM software

• A CAT Comm 3 adapter with all cables

• U.S.-based support and a 30-day satisfaction guarantee

• No VIN lockouts or annual renewals