CHKSuite v1.5: How to Correct ECU Checksums Like a Pro

What Is CHKSuite?

CHKSuite is our standalone checksum correction tool for Windows. It takes a modified ECU binary file, identifies the ECU type, and automatically corrects all checksums — ensuring the file is ready to flash without the ECU rejecting it.

If you modify ECU files yourself (using WinOLS, ECM Titanium, or any hex editor), CHKSuite is an essential part of your workflow. Every modified map changes the file’s data, which invalidates the existing checksums. Without correction, the ECU will detect the mismatch and either refuse to start, enter limp mode, or store fault codes.

Supported ECU Types

CHKSuite supports checksum correction for a growing list of ECU families:

Bosch Diesel (EDC)

• EDC15 (all variants: C0, P+, C2, VM+, C7)
• EDC16 (C0, C2, C3, C4, C34, C35, C39, CP34, U1, U31, U34)
• EDC17 (C10, C46, C50, C54, C60, C64, CP04, CP14, CP20, CP44, CP50, U01, U05, and more)

Bosch Petrol (ME/MED)

• ME7 (7.1, 7.5, 7.8, 7.1.1)
• MED9 (9.1, 9.5)
• MED17 (selected variants)

Siemens/Continental

• SID201, SID206, SID803, SID803A, SID807
• SIMOS (selected variants)

Delphi

• DCM3.4, DCM3.5, DCM3.7, DCM6.2

Magneti Marelli

• MJD6F3, MJD8F2
• IAW (selected variants)

The supported ECU list is updated with each new version. Check our product page for the current list.

Installation and Setup

System Requirements

• OS: Windows 7, 8, 10, or 11
• .NET Framework: 4.7.2 or later
• Disk space: ~30MB
• License: Valid CHKSuite license key (purchased from our store)

Installation Steps

1. Download CHKSuite from our software downloads
2. Extract the ZIP file to your preferred location (e.g., C:\Tools\CHKSuite)
3. Run CHKSuite.exe
4. Enter your license key when prompted (received via email after purchase)
5. The application activates and is ready to use

Step-by-Step: Correcting Checksums

Single File Correction

1. Open CHKSuite and click “Load File”
2. Select your modified ECU binary file — the file you’ve edited in WinOLS or another tuning tool
3. ECU detection: CHKSuite automatically analyses the file and identifies the ECU type. The detected ECU variant is displayed (e.g., “Bosch EDC17C46”)
4. Review the detection: Verify that the detected ECU type matches what you expect. If the auto-detection is wrong (rare), you can manually select the correct ECU type from the dropdown
5. Click “Correct Checksums” — CHKSuite calculates and writes the correct checksum values
6. Save: The corrected file is saved. By default, CHKSuite overwrites the original file. You can also use “Save As” to create a new file.

The entire process takes seconds.

Verification

After correction, CHKSuite displays:

• Number of checksums found
• Number of checksums that were incorrect (and corrected)
• Number of checksums that were already correct
• Correction status: ✅ All checksums correct

Batch Correction

If you have multiple files to correct (e.g., after a batch of tuning work), CHKSuite supports batch processing:

1. Click “Batch Mode”
2. Select a folder containing your modified files
3. CHKSuite processes each file: auto-detects the ECU type and corrects checksums
4. A summary report shows the results for all files

This is particularly useful for file services that process dozens of files daily.

CHKSuite vs WinOLS Built-in Checksums

Both WinOLS and CHKSuite can correct checksums, but they serve different use cases:

When to Use CHKSuite

• You don’t have WinOLS (using ECM Titanium, BitEdit, or hex editor)
• WinOLS doesn’t have a checksum plugin for your specific ECU variant
• You need batch processing for multiple files
• You want a quick verification that checksums are correct before flashing
• You receive files from other sources and want to verify checksum integrity

Common Issues and Solutions

“ECU type not detected”

• The file may be truncated or corrupted — verify the file size matches what your tool read
• The ECU variant may not yet be supported — check the supported list
• Try manually selecting the ECU type from the dropdown

“Checksum correction failed”

• The file may have been modified in the boot/program area (not just the calibration area)
• The file format may not match the expected layout for that ECU variant
• Ensure you’re working with the full flash dump, not a partial read

“Checksums already correct”

• This means the file already has valid checksums — either it hasn’t been modified, or checksums were already corrected by another tool
• This is not an error — the file is ready to flash

Best Practices

• Always correct checksums as the last step — after all map modifications are complete. Don’t correct checksums between individual map edits.
• Keep a backup of the uncorrected file — in case you need to make further modifications and re-correct.
• Verify after correction — reload the file in CHKSuite and verify all checksums show as correct.
• Don’t double-correct — running checksum correction twice shouldn’t cause issues, but it’s unnecessary if the first correction succeeded.

Get CHKSuite from our software downloads section.