Last Updated: May 05, 2021

On Board Diagnostics for St. Charles Motorists

Some St. Charles vehicle owners wonder why Sparks Tire & Auto and other St. Charles auto repair shops charge a fee for vehicle diagnostics.

Receiving a diagnostic charge at Sparks Tire & Auto for a tricky automotive problem shouldn't be a surprise. In the St. Charles area, automotive diagnostics can cover quite a range. If you hear a noise in your vehicle brakes when you slow down in rush-hour traffic on a busy Missouri road, you pull off at the next off-ramp and take a quick visual check. That is usually enough to know what needs to be done. If you're having an intermittent problem with your vehicle engine, however, a Sparks Tire & Auto diagnosis may be much more involved.

Much of the St. Charles driver's confusion comes when the problem involves the Check Engine light. The Check Engine light comes on when the engine management computer has sensed a problem.

There's a common misconception among Missouri drivers that the trouble code tells the Sparks Tire & Auto technician exactly what's wrong. They wonder why there is a diagnostic charge because the scanner quickly gave the diagnosis.

In reality, it is not that easy and straightforward. The computer monitors many sensors throughout the vehicle. When one of these sensors has a reading that's out of parameters, the computer will record a trouble code and turn on the Check Engine light.

The vehicle computer's trouble code just tells the Sparks Tire & Auto technician what engine parameter is out of range, not what's causing it. The technician needs to determine the underlying problem that's causing the malfunction.

There are many problems that could cause a troublesome sensor reading for Sparks Tire & Auto customers. The service advisor makes a list of the most likely causes and begins tracking down the source of the problem. This takes time.

St. Charles service centers subscribe to databases that document possible causes for all the possible trouble codes. The databases outline procedures for confirming a diagnosis and provide the documented repair. These  databases are specific to each vehicle and engine combination.

Some diagnoses are quick and easy. Others are more involved, time-consuming and difficult. Of course Sparks Tire & Auto wants to figure out what's wrong with your vehicle and get you back on the road as quickly as possible.

Sparks Tire & Auto
1665 Scherer Parkway
St. Charles, Missouri 63303
636-946-5900