FORScan Tire Size Calculator
Based on the search results and information provided, here’s a comprehensive table summarizing what you need to know about using FORScan for tire size adjustments:
| Aspect | Details |
|---|---|
| Purpose | Adjust vehicle computer for new tire sizes to correct speedometer and other systems |
| FORScan Version | 2.3.47 and up recommended for tire size corrections |
| Calculation Methods | 1. Nominal tire size input 2. GPS-based calibration |
| Key Parameters | – Tire circumference – Tire dimensions – Final drive ratio |
| Relevant Modules | BCM (Body Control Module), PCM (Powertrain Control Module), TCM (Transmission Control Module) |
| Important Registers | 726-15-01/02 for tire size in some models |
| Measurement Unit | Tire circumference often in millimeters |
| Conversion | Circumference converted to hexadecimal for input |
| Accuracy | GPS method more accurate than nominal size input |
| Potential Issues | – CEL (Check Engine Light) may trigger – P160A code possible with large size changes |
| Post-Adjustment | PCM and TCM relearn may be necessary |
| Vehicle Compatibility | Varies by model; Ford F-150, Edge, Transit commonly discussed |
| Limitations | Some very large sizes (37″+) may cause issues |
| Safety Precautions | Always backup As-Built data before making changes |
| Additional Tools | Spreadsheets available for calculations |
| Verification | Use GPS speed for accuracy check after adjustment |
Remember:
- Always consult model-specific forums or documentation.
- Backup your vehicle’s current configuration before making changes.
- Be prepared to troubleshoot CEL or other issues that may arise.
- For 2022+ models, relearn PCM/TCU/AWD modules after tire size changes.
- Accuracy of speedometer and odometer can affect legal and safety aspects of vehicle operation.