Can Poor Vehicle Maintenance Affect a Personal Injury Claim in Ontario?

October 26, 2026, Kitchener, Ontario

Posted by: Robert Deutschmann, Personal Injury Lawyer

When a serious motor vehicle collision happens, most people immediately think about the drivers involved. Who was speeding? Who failed to stop? Who crossed the centre line?

But sometimes another question matters: Was one of the vehicles properly maintained?

Worn brakes, severely worn tires, defective steering components, broken lights or other mechanical problems can become important evidence when determining how an Ontario collision occurred.

Poor vehicle maintenance does not automatically eliminate an insurance claim. However, if a mechanical problem contributed to the collision or made the resulting injuries worse, it can become part of the legal analysis.

Why Does Vehicle Condition Matter After a Collision?

Ontario personal injury claims generally require an assessment of how the collision occurred and whether another person’s negligence caused the injuries.

Suppose a driver fails to stop at an intersection and strikes another vehicle. The circumstances may appear straightforward. But investigators later discover that the struck vehicle had severely worn tires that reduced traction and increased the stopping distance.

That information could become relevant to determining whether the collision might have been avoided or whether more than one factor contributed to the accident.

This is known as causation: the question of whether a particular act or condition actually contributed to the accident or resulting injuries.

What Vehicle Problems May Be Investigated?

Depending on the circumstances, an insurer, collision reconstruction expert or lawyer may examine:

• Tire tread and tire condition
• Brake pads, rotors and brake performance
• Steering and suspension components
• Headlights, brake lights and signal lights
• Vehicle warning lights
• Previous mechanical defects
• Recent repair recommendations
• Maintenance and inspection records
• Damage patterns following the collision

A vehicle involved in a serious collision may also need to be preserved for inspection before repairs or disposal.

Could Poor Maintenance Lead to Shared Fault?

Potentially.

Ontario law recognizes situations in which more than one person may have contributed to an accident. If a driver's conduct or vehicle condition contributed to the collision, that evidence may become relevant to determining responsibility.

For example, imagine a driver is travelling behind another vehicle during heavy rain. The lead vehicle suddenly stops. The following driver cannot stop because the vehicle's tires are severely worn and loses control.

The fact that the lead driver stopped unexpectedly may be important. But so may the condition of the following driver's vehicle.

The precise allocation of responsibility depends on the evidence and circumstances of the particular collision.

Does Poor Maintenance Mean an Insurance Company Can Deny My Claim?

Not necessarily.

This is an important distinction.

A missed oil change or overdue maintenance appointment does not automatically invalidate an Ontario automobile insurance claim. The issue is generally much more specific: Did the condition of the vehicle have a meaningful connection to the accident or the loss being claimed?

Ontario's automobile insurance legislation also contains specific rules governing accident notification, property damage and claims arising from automobile collisions. For example, the Insurance Act generally requires notice of an accident to the insurer within seven days when the incident is reportable or a claim is intended, subject to exceptions such as incapacity.

Keep Your Maintenance Records

Maintenance records can become valuable evidence after a serious collision.

If possible, keep:

• Brake inspection and replacement invoices
• Tire purchase and installation records
• Repair invoices
• Safety or inspection records
• Records of recommended repairs
• Photos of your vehicle before the collision
• Documentation concerning warning lights or mechanical problems

These records can help establish the condition of the vehicle before the accident rather than relying on assumptions made after the collision.

What If the Other Driver's Vehicle Was Defective?

The issue can also work in the opposite direction.

If another vehicle had a mechanical defect that contributed to your collision, that defect may become part of the investigation.

For example, defective brakes, inadequate lighting or a steering failure could potentially contribute to a collision. Determining responsibility may require evidence from mechanics, engineers, collision reconstruction experts, police reports and other sources.

In some cases, the circumstances may also raise questions about negligent maintenance, repair work or a defective vehicle component.

What Should You Do After a Collision?

If you have been injured, your priority should be your health and safety.

Seek appropriate medical attention, report the collision as required, preserve available evidence and avoid making assumptions about who is legally responsible.

Do not authorize the destruction or disposal of a seriously damaged vehicle if its mechanical condition could be relevant to determining how the collision occurred without first considering whether it should be preserved for inspection.

Most importantly, remember that the insurance company's initial assessment is not necessarily the final legal assessment of liability.

Injured in a Collision in Waterloo Region or Southwestern Ontario?

A serious collision can involve much more than vehicle damage. Questions about liability, contributory negligence, accident benefits, medical treatment, income loss and long-term disability can become increasingly complicated as the claim develops.

If you or someone you love has been injured in a motor vehicle collision, speaking with a personal injury lawyer early can help you understand your rights and what evidence may be important.

Deutschmann de Koning Law represents injured people throughout Waterloo Region and Ontario.

The condition of a vehicle can sometimes be an important piece of the collision puzzle. Understanding that evidence early can make a significant difference to how a personal injury claim is investigated and advanced.

About Deutschmann de Koning Law

Deutschmann de Koning Law serves South-Western Ontario with offices in Kitchener-Waterloo, Cambridge, Woodstock, Brantford, Stratford and Ayr. The law practice of Robert Deutschmann and Nick de Koning focuses almost exclusively in personal injury and disability insurance matters. For more information, please visit www.ddinjurylaw.com or call us at 1-519-742-7774.