Back to all

On Board Diagnostics for Joliet Motorists

October 7, 2018

Some Joliet vehicle owners wonder why Tuffy Joliet (South Plainfield) and other Joliet auto repair shops charge a fee for vehicle diagnostics.

Receiving a diagnostic charge at Tuffy Joliet (South Plainfield) for a tricky automotive problem shouldn't be a surprise. In the Joliet 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 Illinois 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 Tuffy Joliet (South Plainfield) diagnosis may be much more involved.

Much of the Joliet 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 Illinois drivers that the trouble code tells the Tuffy Joliet (South Plainfield) 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 Tuffy Joliet (South Plainfield) 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 Tuffy Joliet (South Plainfield) customers. The service advisor makes a list of the most likely causes and begins tracking down the source of the problem. This takes time.

Joliet 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 Tuffy Joliet (South Plainfield) wants to figure out what's wrong with your vehicle and get you back on the road as quickly as possible.

Tuffy Joliet (South Plainfield)
2031 SR 59
Joliet, Illinois 60586
815-436-1829

More articles from Tuffy Joliet

Custom Wheels and Tires for Your Joliet Ride

April 19, 2026

It seems like everywhere you go in the Joliet area you see custom wheels. Big trucks, little cars, mini-vans - it doesn't matter - are expressing themselves with custom wheels. Some Illinois auto owners want smaller tires and wheels - some want larger - and some want them enormous. So where do... More

Cabin Air Filter and Engine Air Filter: What’s the Difference?

April 15, 2026

You may have heard someone say they just got the air filter replaced in their vehicle. But did you know your vehicle has two different major air filters and they both perform quite differentbut very importantduties? Todays vehicles have a cabin air filter, and an engine air filter. The engine a... More

Go with the Flow (MAF Sensor Replacement)

April 14, 2026

If your vehicle has an internal combustion engine, it depends on two things to make propulsion power for you to be able to motor on down the road: fuel and air. The engine mixes the two in just the right proportion so that they can be ignited, creating a series of tiny explosions that are coordi... More