The Dreaded Check Engine Light

By Mister Transmission

Some of us are old enough to remember the pre-1981 vehicles, which weren’t equipped with on-board diagnostic systems. Much has changed and now we can learn about problems before they ruin our ride!

Cars born before 1981 would indicate a malfunction usually through one of four “idiot” lights, which would tell us that our car had lost oil pressure, over-heated, stopped charging the battery, or lost brake pressure. The problem with these lights is that they usually came on after the damage was already done due to their simplistic sensor systems.

Also, these sensors and systems didn’t give a hoot what was coming out of our tailpipes as far as pollution was concerned. That changed in 1981 when new regulations came out requiring catalytic converters for all domestic passenger vehicles.

The Advent of On-Board-Diagnostics

It was taken a step further in 1996 when automakers were required to upgrade their vehicles to a sophisticated system consisting of central processing units (CPU), sensors, actuators and valves known as OBD II (On-Board Diagnostics). When a problem with the vehicle’s engine, transmission, emission system or any of the myriad of sensors monitoring the aforementioned systems occurs, a code is stored in the computer and the “engine light” is illuminated to alert the driver.

As you may know, almost everyone (including the manufacturers who should know better) refers to the light as “the engine light”. This is one of those situations where one of the first manufacturers to equip their vehicles with on-board diagnostic (OBD II) systems called it an engine light, and now it’s the generic name for lights of that nature.

A few manufacturers did refer to it more accurately by calling it the Malfunction Indicator Light (MIL), since it true purpose is to indicate a malfunction in the systems the computer monitors, but not many.

The problem causing the light to come on could very well be a transmission fault. A technician would perform a scan to retrieve the trouble code from the computer and then cross-reference it to determine what area is at fault.

Where most technicians make an error, is to find a transmission-related trouble code in the computer, and then assume that it merely needs a flush, service, or “magic potion” poured into it to correct the problem. Fluids or aftermarket additives cannot fix worn clutch plates, broken gears or defective solenoids… only replacing them can.

When your vehicle has a transmission-related fault code in the computer, let us remove the pan for a visual inspection. If there is excessive metal on the magnet and/or the fluid is burnt, the transmission is going to need to come out.

If your engine light is on, please contact your local Mister Transmission and book an appointment for our FREE 21-Point Multi-Check Inspection which includes removing the pan on your transmission.

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Customer Reviews
Experience and knowledge in all...
Eduardo Gallon
Experience and knowledge in all aspects of transmissions, with fast turnaround time on repairs
Date: July 11, 2025
Website: Google
Mister transmission was absolutely amazing...
CheriPie
Mister transmission was absolutely amazing to work with. I was freaking out and stressed knowing how expensive a transmission issue can be. I was referred from my mechanic for transmission issues and from the beginning of the referral, I was informed of everything that was going on and what they were doing. They were amazing to answer my questions and concerns and were very patient with me while I was able to work out a payment. The lady at the front desk was amazing and so professional and wonderful to talk to. They were able to get my jeep in very quickly and diagnosed. Once they Started the repair. It was so fast. Thank you so much for getting my vehicle back on the road so quickly. I highly recommend them for any transmission service or repair. Just an all around amazing experience. Thank you Mister Transmission!!!
Date: July 10, 2025
Website: Google
Always a great experience here....
Crystal Garbutt
Always a great experience here. The manager goes above and beyond to make sure you are satisfied with the outcome. Special thanks to Dan and his team for making sure my daughter’s car was safe for her and my grandbabies to drive. It’s nice to find a mechanic you can trust and feel confident in. Highly recommend this location.
Date: July 10, 2025
Website: Google
My car faced a shifter...
Victor Fernandes
My car faced a shifter malfunction related issue. I was referred to Mister Transmission and I must say that Aki and his crew went above and beyond to assist. Every member of the team including Aki, Victor at Front Desk, the Technicians working diligently on the workshop floor were all supportive and keen to assist. Aki also took the time to explain the issue in detail and also demonstrated the problem my car faced with a diagrammatic representation to help me better understand. I am extremely pleased with the levels of service, support and reassurance offered. In addition, Aki’s knowledge of transmission systems reigns supreme and it is evident that this expertise has been acquired practicing his trade over decades. Customers benefit most from this experience as Aki has an extremely thorough understanding and a deep sense of what is causing the issue on hand. Would strongly recommend Mister Transmission (Dundas and Shawson/Britannia) in Mississauga.
Date: July 10, 2025
Website: Google
Mister transmission was absolutely amazing...
CheriPie
Mister transmission was absolutely amazing to work with. I was freaking out and stressed knowing how expensive a transmission issue can be. I was referred from my mechanic for transmission issues and from the beginning of the referral, I was informed of everything that was going on and what they were doing. They were amazing to answer my questions and concerns and were very patient with me while I was able to work out a payment. The lady at the front desk was amazing and so professional and wonderful to talk to. They were able to get my jeep in very quickly and diagnosed. Once they Started the repair. It was so fast. Thank you so much for getting my vehicle back on the road so quickly. I highly recommend them for any transmission service or repair. Just an all around amazing experience. Thank you Mister Transmission!!!
Date: July 10, 2025
Website: Google
Everyone was exceptional! Very transparent...
Stephanie B
Everyone was exceptional! Very transparent about each step and what they found and what it would cost before hand
Date: July 10, 2025
Website: Google
My first experience with Mister...
Natalie And
My first experience with Mister Transmission was great! Their inspection was thorough and they were honest about what actually needed fixed and didn't try to push unnecessary work. Highly recommend
Date: July 9, 2025
Website: Google
Great customer service, got in...
Marc S.
Great customer service, got in quicky, problem solved on time and on budget.
Date: July 8, 2025
Website: Google
Exter road mister transmission was...
Brian Linhares
Exter road mister transmission was great in servicing my vehicle. Sanjay was great and kind in helping me and fair in pricing. Overall great place to take your vehicle and great customer service
Date: July 8, 2025
Website: Google
Barry is one of the...
Josh Anderchek
Barry is one of the best. Straight up, tells you how it is, no swerves or anything.
Date: July 8, 2025
Website: Google
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