25VIN02 — Change-of-Engine VIN Inspections: What Dealers Should Know

Why Engine Swaps Trigger VIN Scrutiny in California

The California DMV has issued VIN Bulletin 25VIN02, specifically addressing VIN inspections involving engine changes. For dealers, verifiers, and rebuilders, understanding this bulletin is crucial — especially when dealing with high-performance swaps, emission upgrades, or replacing damaged engines.

Let’s break down what changed and how you can stay compliant.



What Is Bulletin 25VIN02?

VIN Bulletin 25VIN02 focuses on vehicles that have undergone engine replacement, modification, or enhancement. It updates the inspection process for:

  • Matching VINs to altered powertrain components
  • Confirming emissions equipment compatibility
  • Ensuring correct engine labeling and documentation

This is especially important for salvage vehicles, rebuilt titles, or custom performance builds.



Woman inspecting vehicle in dealership showroom, representing VIN inspection and engine modification compliance in California.

Key VIN Inspection Updates in 25VIN02

1. Verification of Engine Block Serial Number

  • Verifiers must now document the engine block number when it differs from DMV records.
  • The number must be clearly visible or accompanied by manufacturer documentation.

 2. Smog Compliance Labeling

  • If the engine comes from a newer or different vehicle, dealers must:
    • Show an emissions label on the donor engine
    • Confirm compatibility with California Emissions Standards
    • Submit BAR referee documentation if needed

3. REG 31 Requirements

  • REG 31 must include:
    • Engine type and size (e.g., 2.0L I4, 3.5L V6)
    • Whether the engine change affects the vehicle’s classification
    • All VIN-related adjustments must be explained in Section C

4. Inspection Conditions

  • The engine must be fully installed and operable.
  • Incomplete swaps or vehicles under modification cannot be verified.

Common Issues That Can Lead to DMV Rejection

  • Engine numbers that don’t match the DMV database
  • Missing smog/emission tags or referee reports
  • REG 31 forms without a change-of-engine annotation
  • Attempting to verify vehicles in mid-swap condition

Why This Matters for Dealers

Mistakes during VIN inspections on engine-swapped vehicles can:

  • Delay or block title issuance
  • Result in rejected DMV paperwork
  • Create liability for dealers if the buyer cannot register the car

Knowing the 25VIN02 requirements means less back-and-forth with the DMV and more efficient processing.

California DMV REG 31 form used for vehicle VIN verification and engine change documentation during inspections.

Required Forms & Resources

  • REG 31 – Verification of Vehicle
  • BAR Referee Inspection Info
  • California Emissions Guidelines

 References

  1. California DMV VIN Bulletin 25VIN02 (PDF)
  2. GotPlates.com Licensing Courses
  3. Bureau of Automotive Repair (BAR)