What OEM Repair Procedures Are
OEM (Original Equipment Manufacturer) repair procedures are the vehicle manufacturer's official instructions for repairing their vehicles. Each procedure specifies: where to cut for panel sectioning (and where cutting is prohibited), which joining method to use at each joint (MIG weld, STRSW, adhesive, rivet), material specifications for the replacement panel, corrosion protection requirements (weld-through primer, epoxy, cavity wax, seam sealer), and any special tools or equipment required.
These procedures are developed by the manufacturer's engineering team based on the vehicle's structural design, crash performance requirements, and material properties. They're not suggestions — they're the engineering specifications that ensure the repaired vehicle performs as designed in a subsequent collision.
Why OEM Procedures Matter
Safety
Modern vehicle body structures are engineered to manage crash energy through specific load paths. Cutting a panel in the wrong location, using the wrong joining method, or substituting materials can disrupt these load paths — creating a vehicle that doesn't protect its occupants as designed in a future collision. A quarter panel sectioned at the wrong location may fold instead of absorbing energy. A B-pillar welded where adhesive bonding was specified may crack at the weld HAZ under crash loads.
Liability
If a vehicle is involved in a collision after repair and the repair is found to deviate from OEM procedures, the repairing shop faces potential liability for any injuries that the non-compliant repair may have contributed to. Documented adherence to OEM procedures provides legal protection — the shop followed the manufacturer's engineering specifications. Deviation from OEM procedures shifts the engineering responsibility from the manufacturer to the shop.
Certification
OEM certification programs (Honda ProFirst, Toyota Certified Collision Center, Ford, GM, FCA, Tesla, and others) require documented use of OEM repair procedures on every structural repair. Certified shops that deviate from procedures risk losing certification — and the customer referrals and business that come with it.
Where to Access OEM Procedures
Manufacturer Service Information Portals
Each manufacturer provides repair procedures through their service information website. Access is typically subscription-based ($20–100 per day or $500–3,000 per year depending on the manufacturer). Some portals:
Toyota: TIS (Toyota Technical Information System). Honda: ServiceExpress. Ford: Motorcraftservice.com. GM: ACDelco TDS. Stellantis (FCA): TechAuthority. Tesla: service.tesla.com. BMW: TIS Online. Mercedes-Benz: STAR TekInfo.
Aggregated Databases
I-CAR's Repairability Technical Support (RTS) portal aggregates OEM repair procedures from multiple manufacturers in one searchable interface. Many shops prefer RTS because it eliminates the need for separate subscriptions to each manufacturer. OEM1Stop.com provides links to all manufacturer portals from a single page.
Collision Repair Network Databases
CCC, Mitchell, and Audatex estimating systems include links to OEM repair procedures within their platforms. Clicking on a repair operation in the estimate opens the relevant OEM procedure — integrating the procedure lookup into the estimating workflow.
How to Read a Repair Procedure
Sectioning Guidelines
The procedure specifies exactly where a panel can be sectioned (cut for partial replacement) and where sectioning is prohibited. Cut lines are typically shown on a vehicle diagram with precise measurements from reference points (factory seam locations, body line intersections, structural joints). Prohibited zones — areas where cutting would compromise structural integrity — are marked in red or with "do not section" callouts.
Follow the cut line locations exactly. Moving a cut line 2 inches to "make it easier" or to "avoid a body line" may place the section joint in a load path or material zone that the manufacturer tested and rejected. The specified cut location was chosen through crash testing and structural analysis — it's not arbitrary.
Joining Methods
Each joint in the procedure specifies the joining method: MIG plug weld (number of plugs, spacing, hole diameter), STRSW (number of spots, spacing), adhesive bond (adhesive type, bead pattern, clamping requirements), self-piercing rivet (rivet type, spacing, tool requirements), or a combination (weld-bond, rivet-bond).
Don't substitute joining methods without explicit OEM authorization. "We don't have an STRSW machine so we'll plug-weld instead" is a deviation from the OEM procedure — even if the plug weld is structurally adequate. If the procedure specifies STRSW and you can't perform STRSW, either acquire the equipment or subcontract to a shop that has it.
Material Specifications
The procedure identifies the material type and grade at each panel location: mild steel, HSS (with MPa rating), UHSS (with MPa rating), boron steel, aluminum (alloy designation), or composite. Material specifications determine welding parameters, heat treatment restrictions (no welding on certain UHSS grades), and compatible repair methods.
Don't assume a replacement panel is the same material as the original just because it looks the same. A UHSS B-pillar reinforcement looks identical to a mild steel one but has completely different repair restrictions. Verify the material specification in the OEM procedure and ensure the replacement panel matches.
Corrosion Protection
The procedure specifies corrosion protection at each stage: weld-through primer on mating flanges, epoxy primer on all bare metal, seam sealer type and pattern at each joint, cavity wax in enclosed sections, and undercoating on exposed underbody surfaces. Follow every corrosion protection specification — they're not optional enhancements, they're engineered protection layers that prevent structural degradation over the vehicle's remaining service life.
Documenting Compliance
Document every step of the repair with photographs that show: the damage before repair, the sectioning cuts at the OEM-specified locations, the joining method at each joint (plug welds, STRSW spots, adhesive beads), corrosion protection application (epoxy primer, seam sealer, cavity wax), and the completed repair before paint. These photos, along with the OEM procedure printout and the repair order, create a defensible repair file that demonstrates compliance with the manufacturer's specifications.
Store repair documentation digitally for at least 7 years (longer in some jurisdictions). If a liability question arises years after the repair, the documentation proves the shop's work met the engineering standard in effect at the time of the repair.
When Procedures Aren't Available
Some older vehicles, low-volume models, and certain aftermarket modifications don't have published OEM repair procedures. In these cases, use I-CAR general repair guidelines as a baseline, apply industry-standard practices for the material type, document the approach taken and the rationale, and note in the repair file that no OEM-specific procedure was available. This documentation shows due diligence even without a vehicle-specific procedure.
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