Written by: Erin Vaughan - President, CEO and Journeyperson Automotive Service Technician
My Check Engine Light Is On: What Does It Actually Mean?
Your check engine light comes on, so you plug in a code reader or stop somewhere that offers a quick code scan. The code reader or nice parts salesman tells you the code. “It needs an oxygen sensor.” But does it? Not necessarily.
One of the biggest misconceptions about modern vehicles is that plugging in a scan tool tells a technician what's wrong. In reality, a trouble code tells us where to start looking. It isn't the diagnosis.
What Does a Check Engine Light Mean?
There are hundreds of reasons your check engine light can turn on. The vehicle's computer has detected something outside the conditions it expects and stored a diagnostic trouble code. That code provides information that helps a technician determine which system needs to be investigated. The actual problem could involve a sensor, wiring, an actuator, a mechanical component, a module or something affecting another system entirely. That's why replacing the part mentioned in a trouble code can become an expensive guessing game.
Can I Keep Driving With My Check Engine Light On?
Sometimes, but not always.
If the check engine light is solid and your vehicle is otherwise running normally, it may not be an immediate emergency. You should have the problem diagnosed rather than ignoring it indefinitely, but neither you or the vehicle are in immediate danger. Continuing to drive with certain faults can increase fuel consumption, affect how the vehicle runs or eventually contribute to more expensive problems.
There are also situations where you should stop driving.
Safely stop your vehicle if:
- The check engine light is flashing
- The engine is shaking or running extremely poorly
- You hear an unusual engine noise
- The oil-pressure warning light is also illuminated
- The vehicle displays a reduced-power warning
- The vehicle otherwise feels unsafe to drive
When you're unsure, call us before continuing to drive.
Doesn't the Trouble Code Tell You What's Wrong?
No, and this is where proper automotive diagnosis by a professional matters.
Imagine a vehicle has a code indicating that the engine is running lean. An oxygen sensor might report the lean condition, but that doesn't automatically mean the oxygen sensor has failed.
The actual cause could be something such as:
- A weak fuel pump
- A vacuum leak
- A leaking purge valve
- A mass airflow sensor problem
- Damaged wiring
- Another mechanical or electrical fault
Replacing the oxygen sensor without testing the system could leave you with the same check engine light and you lost money on a new part you didn't need.
The trouble code gives us a place to start, testing determines why the code was set.
Even a Misfire Code Can Have Many Causes
A misfire sounds fairly straightforward, but there can be many possible causes.
Depending on the vehicle and symptoms, a misfire could involve a:
- Spark plug
- Ignition coil
- Fuel injector
- Wiring problem
- Oxygen sensor
- Camshaft or crankshaft sensor
- Purge valve
- Plugged catalytic converter
- Valvetrain problem
- Piston or other internal engine problem
- Leaking head gasket
- Engine control module
That's why we don't want to start replacing parts simply because they're associated with a particular code.
How Does Kinetic Diagnose a Check Engine Light?
At Kinetic Auto Service, diagnosis starts with understanding what the vehicle is actually doing. When appropriate, we'll test drive the vehicle so we can experience the symptoms you're describing and listen for anything unusual. Then we'll connect professional diagnostic equipment and retrieve the trouble codes and other information stored by the vehicle. That's the beginning of the diagnosis, not the end.
Depending on what we find, the next steps may include following manufacturer diagnostic procedures and testing:
- Sensors
- Wiring and electrical circuits
- Actuators and solenoids
- Control modules
- Mechanical components
- Live vehicle data
Professional scan tools can do considerably more than simply read trouble codes. They allow technicians to monitor what sensors are reporting in real time and, on many vehicles, command components to operate so their response can be tested. We also use technical information including manufacturer specifications, wiring diagrams, diagnostic procedures and repair information to determine what should happen, then compare that with what the vehicle is actually doing.
Today's Vehicles Really Are Computers on Wheels
Modern vehicles contain interconnected computers, sensors, wiring, modules and electronically controlled components throughout the vehicle.
And those systems operate in our harsh Saskatchewan climate!
They experience summer heat, extreme winter cold, snow, water, dirt, rough roads, vibration and even damage from rodents or insects.
When something stops working properly, determining WHY can require systematic testing rather than simply looking for a visibly broken part.
Isn't It Cheaper to Just Replace the Most Likely Part?
Sometimes you might get lucky 🍀
But when the guess is wrong, you've paid for a part and labour, while still having the original problem. Then you have to pay to diagnose it anyway. That's why our approach is to test first and repair second.
Proper diagnosis can cost more initially than having someone scan a code and make a guess. But the goal isn't to find the cheapest possible first step.
The goal is to identify the root cause so you're spending your repair dollars fixing the actual problem.
How Much Does Check Engine Light Diagnosis Cost?
There isn't one diagnostic charge that applies to every check engine light because different problems require different amounts of testing.
Most concerns can be diagnosed with approximately one to two hours of diagnostic time, although complex problems can require additional testing.
We'll explain what is required as we work through the diagnostic process and you will never get charged more than what you’ve agreed to!
What Happens After Kinetic Finds the Problem?
Once we've identified the root cause, we'll explain what we found and recommend the full and complete repair.
We want you to understand what failed, why we're recommending the repair and what you're paying to fix.
And we stand behind our diagnosis. If we've misdiagnosed the concern, we're not going to expect you to keep paying while we throw more parts at the vehicle.
Check Engine Light On in Regina?
If your check engine light is on, or your vehicle is experiencing a warning light, driveability problem, unusual noise or other concern, Kinetic Auto Service can diagnose what's actually happening.
Don't start with throwing parts at the problem, start with finding the root of the problem.
Book Online or Call today to get your vehicle professionally diagnosed at Kinetic Auto Service.
