On-Board Diagnostics

Sun Automotive technicians have been using a standardized diagnostic system to help determine what is wrong with a vehicle since 1996. This diagnostic system works in tandem with the Engine Control Modules for each vehicle’s engine. The Engine Control Module is a computer that monitors and controls many engine functions.

Sensors throughout a vehicle send readings to the Engine Control Module. These readings help the computer make adjustments in various vehicle systems to allow for constantly changing driving conditions and to compensate for minor problems. However, if the computer encounters a situation it can’t adjust for, it turns on the Check Engine light. (The Check Engine light is called the “service engine soon” light on some vehicles.)

If the Check Engine light is burning steadily, it indicates a problem that needs to be taken care of soon. However, if it is flashing the vehicle needs immediate attention. When the Check Engine light is flashing, the vehicle should not be driven at high speeds, haul heavy loads or tow a trailer. Drivers need to understand that doing so can cause major damage.

When a vehicle is brought to Sun Automotive because the Check Engine light is on, a technician will scan the Engine Control Module to learn why it turned the light on. The answer comes as a “trouble code.” The technician has access to software that allows him to enter the code and find out what it means. The software will also let your Sun Automotive technician know what might be causing the problem and how to diagnose it.

While the trouble code does not tell your technician at Sun Automotive exactly what is wrong with the vehicle it can let him know where to start looking to find the problem.

Scanning a trouble code and determining what it means is fairly simple for the pros at Sun Automotive. But the ensuing process of actually diagnosing a vehicle’s trouble can take a skilled technician some time. This can add up to a significant repair bill. Some vehicle owners mistakenly believe that the “trouble code” is all they need and think they can then fix their vehicles themselves. Some have tried to save money by purchasing an inexpensive scanner, or they take their vehicles to an auto parts store that offers the scan for little or no cost.

These options are often not the money-savers they seem for vehicle owners and can end up costing extra repairs and engine damage

It is important to remember that inexpensive scanners don’t have the ability to read the history stored in an engine’s computer. This operating history contains clues that can help in diagnosing engine trouble since it can indicate a developing problem. Sun Automotive invests a lot of money in high-end diagnostic equipment so that we have access not just to service codes but also to the operating history of the engine.

While on-board diagnostics are a tool to help diagnose what is wrong with a vehicle they cannot specify what part needs to be fixed or replaced, and they cannot replace a well-trained and well-equipped service technician.