Last Updated on July 20, 2023 by Henry T. Hawkins
If you own a diesel truck, you may have experienced the frustration of seeing the check engine light turn on. While it may be tempting to ignore it and hope for the best, this warning signal should never be taken lightly. The check engine light can indicate many problems, some of which can be serious and expensive.
In this blog post, we’ll take a closer look at the reasons why the check engine light might come on in your diesel truck and what you can do to address the issue.
- Why Is My Diesel Truck Check Engine Light On?
- What To Do When Your Diesel Check Engine Light Comes On?
- Frequently Asked Questions
Why Is My Diesel Truck Check Engine Light On?
Here is a list of 10 common reasons why the check engine light may come on in a Diesel Truck
Bad O2 Sensor:
The check engine warning light may indicate a bad sensor. The O2 sensor measures the exhaust oxygen levels of the vehicle, and a defective sensor may result in the black exhaust, a sputtering engine, or rough idling.
Loose or Defective Gas Cap:
A loose fuel cap may cause the check engine light on but car runs fine. A defective cap may also cause issues in the gas tank delivery system.
The after-treatment system is another common reason why the check engine light may come on in a diesel truck. Diesel trucks have nitrogen oxide (NOx) sensors that measure the vehicle’s emissions, and a malfunctioning after-treatment system may cause issues with the emissions system.
Vacuum system performs a wide variety of functions. The check engine light can come on due to various reasons, and a vacuum leak is one of them.
When your diesel truck’s engine has a vacuum leak, it can cause a variety of symptoms, such as rough idle, misfires, decreased acceleration, and even stalling. Additionally, the vacuum leak can cause the engine to run lean, which can trigger the check engine light.
Exhaust Gas Recirculation (EGR) System:
A malfunctioning EGR system may cause the check engine light to come on in a diesel truck. The EGR system recirculates exhaust gases to reduce emissions, and a malfunction may cause issues with the engine’s performance.
Diesel Particulate Filter (DPF):
A clogged or malfunctioning DPF may cause the orange check engine light on in a diesel truck. The DPF traps soot and other particulate matter in the exhaust system, and a malfunction may cause issues with the emissions system. This will eventually reduce engine power until the problem is resolved.
A malfunctioning turbocharger may cause the check engine light to come on in a diesel truck. The turbocharger boosts the engine’s power by compressing air, and a malfunction may cause engine performance issues.
Faulty Mass Air Flow (MAF) Sensor:
Issues with the mass airflow sensor can lead to stalling and decreased fuel efficiency. The check engine light can identify any malfunctions with the mass air flow sensor.
Ignition System Issues:
Issues with the ignition system may cause the check engine light to come on in a diesel truck. Malfunctions with spark plugs or ignition coils may cause issues with the engine’s performance.
Low Fuel Pressure:
Low fuel pressure may cause the check engine light on in a diesel truck. A malfunctioning fuel pump or fuel pressure regulator may cause issues with the engine’s performance.
Issues with the transmission may cause the check engine light to come on in a diesel truck. Malfunctions with the transmission control module or other transmission components may cause issues with the engine’s performance.
Also read: Symptoms of Bad Tie Rods
What To Do When Your Diesel Check Engine Light Comes On?
When you are having engine issues diesel check engine light comes on, it can be concerning and leave you wondering what to do next. Here are some steps you can take to address the issue:
Step 1: Don’t Ignore the Light
Ignoring the check engine light on your diesel truck is not recommended. It could indicate a minor issue or a serious problem that needs immediate attention. Continuing to drive your truck without addressing the issue could potentially cause further damage and lead to costly repairs.
Step 2: Check Your Gas Cap
One of the most common reasons for a orange check engine light on in a diesel truck is a loose or faulty gas cap. Make sure your gas cap is tightened properly and in good condition. If it’s damaged or missing, replace it with a new one.
Step 3: Check for O2 Sensor Issues
A faulty oxygen (O2) sensor is another common reason why the check engine light comes on in a diesel truck. The O2 sensor measures the exhaust oxygen levels in your vehicle. A malfunctioning sensor can cause excess black exhaust, a sputtering engine, or rough idling. Have a mechanic check your O2 sensor to determine if it needs to be replaced.
Step 4: Check Your Aftertreatment System
Another common reason for the check engine light to come on in a diesel truck is an issue with the after-treatment system. This system is responsible for reducing emissions in diesel engines, and a malfunction can cause the check engine light to turn on. A professional mechanic can diagnose and repair any issues with your after-treatment system.
Step 5: Use an OBD Reader
You can use an OBD code reader to check for common engine faults without paying a mechanic. OBD readers are not expensive, and they can help you determine the cause of the check engine light.
If you don’t want to buy an OBD reader, check with your repair shop to see if they offer code reading services.
Also read: Does brake cleaner damage tires
Frequently Asked Questions
Can I continue driving my diesel truck if the check engine light is on?
We do not recommend continue driving your diesel truck if the check engine light is on. Driving with a check engine light could cause more damage to your vehicle and potentially result in costly repairs.
What happens if I ignore the check engine light on my diesel truck?
Ignoring the check engine light on your diesel truck could result in more severe and costly issues with your vehicle’s engine or emissions control system. It is best to address the issue as soon as possible to prevent further damage.
How can I prevent the check engine light from coming on in my diesel truck?
Regular maintenance and upkeep of your diesel truck can help prevent the check engine light from coming on. This includes routine oil changes, replacing air filters, and ensuring that your vehicle’s emissions control system is functioning properly.
If you’re the owner of a diesel truck and the check engine light comes on, it’s essential to take action immediately. Ignoring the warning signal can lead to bigger problems and costlier repairs down the line. By understanding the common reasons why the check engine light might come on, you can be better equipped to diagnose and fix the issue.
Whether it’s a faulty oxygen sensor, a loose fuel cap, or a problem with the after-treatment system, prompt attention and action can help keep your diesel truck running smoothly and efficiently for years.