What to do When the Check Engine Light Comes On

The check engine light in a truck has become much less mysterious than it used to be. What was once a single light with little to no accompanying information might now be three or four different lights with sophisticated displays hinting to where an issue in the engine is occurring. If you notice that your check engine light is illuminated, we recommend taking the following steps:

1. Read Fault Codes

Fault codes are populated by the engine control module when it receives data from sensors that is incorrect, missing, or out of the normal range. This then triggers the check engine light to illuminate. Every model of truck or bus will have its own unique fault codes; some makes of trucks have displays which can give further information as to what component or system is causing the faulty code, while others are more difficult to decipher. A quick Google search can sometimes give you some further information. If you are not sure as to what can be causing your light to illuminate the best decision is to gather as much information as possible as to what is happening and call a qualified truck repair expert for help and a suggestion of how to proceed.

2. Determine Urgency

A check engine light might illuminate due to low fluid, in which case you can simply add coolant or water and continue driving for a short period of time until you are able to see a repair specialist. However, if you see from the fault code that the truck is overheating, this is a rather urgent issue more likely to require roadside assistance or towing depending on the cause of the overheat. Fault codes exist to help determine what engine system or components the problem might be. There are many different possibilities as to why a check engine light will illuminate. Some can be a simple repair as a coolant leak or a broken belt causing an overheat while some require extensive diagnostics and testing to determine the cause of the fault code.

3. Get to the Shop

It can be tempting to continue driving with the check engine light on, especially if you don’t feel any difference in how the engine is running. If you do keep driving for an extended period of time, you could be at risk of the engine derating, which means the engine will eventually reduce power and you will not be able to drive at a normal speed. Some engines will even shut down completely.

To prevent any further engine damage and to avoid going into derate mode, always bring your truck into a repair shop as soon as you see the check engine light illuminated. At On-Site, we can quickly and easily hook your truck up to diagnostic computers to determine what’s going on, fix the issue, and get you back on the road. Visit any of our four locations in New Jersey – we’re open until midnight to minimize your downtime!

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