Check Engine Light

So there’s something not quite right about the way your vehicle is driving, or you’ve got a warning light on your dashboard that was blinking at you yesterday and now it is on steady. What do you do? Hint: the answer is not to put a piece of electrical tape over the warning light and ignore it.

What makes a warning light come on?
Today’s vehicles are manufactured with complex inter-related systems. On-board computers continuously monitor and store information concerning the performance of these systems. A warning light comes on because the computer has sensed a signal from one of the systems or components that has gone outside of its normal operating range. The computer then sends a signal to turn on the light to let you know something is wrong!

Some of the potential causes for a check warning light are not properly tightening your gas cap to engine, transmission or braking system performance issues. While warning lights can go on and the car still appears to be driving “fine”, ignoring some lights can lead to serious issues, such as engine damage or other component failure. In some instances, this can be a safety hazard. That’s why it is recommended to be safe (give yourself peace of mind) and have your car looked at by a certified professional as soon as possible.

How can Dave’s Auto Center “diagnose” my problem?

1. RETRIEVE DATA – A full functioning scan tool is used to perform an onboard computer system analysis in order to retrieve the following:

• Computer codes
• Freeze frame data
• Computer software version numbers
• Critical sensor data and status information

NOTE: Merely “pulling codes” does not generally provide enough information to make an accurate diagnosis of the problem. Pulling codes is the initial step in the process by identifying the circuit or system that has illuminated the vehicle’s check engine light.

2. VERIFICATION TESTING – Verification tests determine if systems meet proper specifications. These tests may include an analysis of:

• Engine vacuum and backpressure
• Mechanical and electrical engine timing
• Ignition system
• Fuel system
• Emissions system

NOTE: Failure in any of these basic systems can cause the check engine light to illuminate and falsely identify a circuit or component as the problem, which could lead to improper or unnecessary parts replacement.

3. PINPOINT TESTING – All manufacturers require that circuit or component pinpoint testing is done in order to make an absolute diagnostic determination. These actions involve:

• Working through wiring diagrams
• Performing electrical and/or mechanical tests
• Performing bi-directional control tests
• Visual inspections of suspect areas

4. RESEARCH TECHNICAL SERVICE BULLETINS – Technical Service Bulletins and hotline information will indicate if the problem has been determined to be a pattern failure, meaning that it is a known issue that occurs with a particular type of vehicle. This does not eliminate the need for testing, as other systems must meet specifications before a service bulletin procedure should be performed.

5. CAR REPAIR – This may involve multiple actions such as:

• Parts replacement
• Cleaning of passages, connections and/or components
• Performing manufacturer technical service bulletin updates
• Updating of vehicle’s computer software
• Wiring repair or replacement

6. VERIFY REPAIR – Once all necessary actions have been taken, the vehicle must be retested to verify that the repair is complete and has achieved the proper results.

How long will it take to diagnose my problem?
In most cases, we can actually find AND fix the problem in the same day.

Do I need an appointment?
Most centers do not require an appointment, but please call your local center for details. It is our goal to make it convenient and offer what works best for you.

Why does my parts store offer to “do my check engine light” for free?
Parts stores capabilities are limited to only reading the stored trouble codes, but they do not then perform the diagnostic procedures to determine what is exactly required to fix your vehicle. Dave’s Auto Center has certified technicians, whose job it is to fix cars!

What are examples of driveability issues that require diagnostics?
Typical driveability issues that require a diagnosis on your vehicle are:

• Any warning lights on the dash that are illuminated (Check Engine Light, ABS, etc.)
• Emissions failures
• Engine or transmission performance
• Steering and ride control

All of the parts we install are guaranteed to meet or exceed manufacturer standards, and if you wish, we’ll return all of your old parts to you.

This service, like all services performed at Dave’s Auto Center, is advised based on your manufacturer’s recommendations, or as needed as determined by our inspection and based on industry standards.

Bountiful, Layton, Salt Lake City

Should you replace your engine or buy a new car? Read our blog post about it https://davesautorepairutah.com/replacing-engine-vs-buying-a-new-car/