Discovering a “Service Exhaust Fluid System” warning message on your vehicle can be alarming. To ensure compliance with emission regulations in diesel engines, a properly functioning exhaust fluid system is essential.
This article provides an overview of the exhaust fluid system, explains the warning message, and offers practical solutions to address the issue.
What is a Service Exhaust Fluid System?
If you have a diesel engine, you might have heard of the Service Exhaust Fluid (DEF) system. But what is it exactly?
Well, it is a system that injects DEF into the exhaust stream of your diesel engine to reduce emissions and comply with environmental regulations. DEF is basically deionized water mixed with urea, and it is stored in a separate tank in your vehicle.
When the DEF injector detects that the DEF level is low, it will trigger a warning light on the dashboard. So, how do you clear the service exhaust fluid system?
First, you need to refill the DEF tank with the appropriate fluid. You can buy DEF at most auto parts stores, and it is relatively inexpensive.
Once the DEF tank is refilled, the warning light should go off. However, if the light does not go off or if you still have issues with the system, you might need to take your vehicle to a mechanic. They can diagnose the problem and fix it for you.
In any case, it is essential to maintain your DEF system properly to ensure your vehicle’s compliance with environmental regulations and optimal performance.
How Exhaust Fluid System Works?
The exhaust fluid system utilizes DEF, which consists of approximately 32.5% urea and 67.5% deionized water. The system injects DEF into the vehicle’s exhaust, upstream of the selective catalytic reduction (SCR) catalyst.
The DEF vaporizes and decomposes into carbon dioxide and ammonia. The ammonia then interacts with the catalyst to convert harmful NOx gases into harmless nitrogen and water. This process enables diesel trucks to meet emission standards.
However, it is important to note that DEF is not infinite and requires regular refilling to ensure proper system operation.
What Does Service Exhaust Fluid System Mean?
Service exhaust fluid system signal means something has tampered with a vehicle’s DEF system, thereby displaying a DEF-related trouble code on the dashboard.
When this message surfaces, it necessitates immediate action to prevent the system from further damage that may be costly to fix. Typically, every truck has a designated warning light on the dashboard that triggers whenever you’re running low on diesel exhaust fluid.
So, the driver’s responsibility is to study this warning signal and top off the fluid when necessary in order to avoid any costly damage. The service exhaust fluid system in a 2011 Duramax is a critical issue if you drive a truck with the diesel engine.
However, if you’re experiencing the service exhaust system warning signal on your dashboard, there’s a way out.
causes of Service Exhaust Fluid System Message
Here are the likely causes of the ‘Service DEF System’ message;
#1. Diesel Exhaust Fluid is running low.
If you are driving a modern diesel vehicle, warning lights and messages will pop up whenever the car runs low on DEF. To accurately know how much DEF you need, you should first establish the engine’s efficiency.
A diesel engine consumes DEF at the rate of 2-3% relative to the fuel it consumes. For a 65-gallon fuel tank, you will need between 1.2 and 2 gallons of DEF.
Though you may not need to refill DEF every time you fuel, it is essential to replenish it regularly. Fill up DEF before a long haul to avoid encountering problems along the way.
#2. Contaminated DEF added.
It is possible to add the wrong DEF either because it is substandard or because it has expired. Every DEF container sold has an expiry date indicated on it.
Exposing DEF to extreme temperature, sunlight, and impurities before using it can cause the DEF system to send error codes.
The dash warning lights shown include a solid or flashing check engine light, and the driver will notice a mild to a severe loss of engine power.
#3. The engine idled for more than an hour.
For the new emissions-compliant diesel vehicle, too much idling can be problematic for the DEF system.
When idling is done for more than an hour or longer than the manufacturer’s recommendation, soot builds up in the DPF, hence requiring more frequent regens.
Long idle time causes the DEF to crystallize in the injectors, causing many issues. Observing proper idling for your machine or vehicle helps reduce maintenance costs and saves fuel.
#4. Cold weather.
This is a common problem that people living in cold climates encounter. DEF has a freezing temperature more or less like water.
When the fluid freezes, engine operation becomes impossible. It is a difficult situation to find yourself in because you shouldn’t add additives to the DEF as it will throw off its concentration.
Additives can also damage SCR compounding your problems even further. The SCR systems are designed to provide the necessary heat to the DEF tank to solve the freezing issue.
How to Fix Service Exhaust Fluid System?
Once you spot the service exhaust fluid system signal on your vehicle’s computer system, ensure to fix it immediately.
These service exhaust fluid system reset tips will help you resolve the issue in a few steps. The guide below is for a 2011 GMC Sierra 2500 HD. It can also fix the issue with other diesel car models.
#1. Test the reductant fluid heater.
The reductant fluid heater is responsible for preventing the diesel exhaust fluid (DEF) from freezing in low temperatures. You may want to check out the component if you suddenly see the service DEF system warning message.
So, get a digital multimeter to test for the resistance. Before that, carefully disconnect the vehicle’s Glow Plug Control Module. Then, test the resistance level on the (orange/white) pin 11 and the ground. It should be within 2 – 4 Ohms.
#2. Replace the reductant fluid heater.
If the reductant fluid heater resistance level is inaccurate, you may have to replace the component immediately before proceeding to the next step. However, kindly move to the next step below if the resistance level is okay.
#3. Reset the exhaust fluid system.
Get a working scan tool that can reset a DEF system and plug it into the scan port beneath the dashboard on the driver’s side.
Turn on the scanner and navigate to “Module Setup.” Then, go to “Reductant Fluid.” Thereafter, move to “Tank Level Reset” and reset the system. This will reset the warning to “None.”
After that, navigate back to “Reductant System Data Reset” and engage the reset again here. However, this will throw on the warning signal in a moment and take it out again after a while. Now you’re good to go! You may want to use this video for further guidance.
This recommendation can also be helpful in fixing the service exhaust fluid system in a Chevy Duramax.
FAQs.
Q: How do you clear a diesel exhaust fluid system?
A contaminated diesel exhaust fluid (DEF) system can be cleared using a vinegar solution. Meanwhile, this is how to clear the service exhaust fluid system in your truck: Mix 1 part of vinegar with 3 parts of water.
Then, pour the solution into the diesel exhaust fluid tank. After that, start the truck and run the engine for around 30 minutes. This will allow the vinegar solution to simply reach the pump. After that, drain out the solution and refill the tank with new DEF fluid.
Q: What happens if you drive without DEF fluid?
Driving without diesel exhaust fluid (DEF) will automatically reduce your truck’s engine performance and alter its speed levels. The DEF fluid is a necessity, especially for trucks produced after 2010. It breaks harmful emissions down into non-toxic nitrogen and water.
The DEF fluid reduces emissions by up to a whopping 90%. So, running out of DEF fluid may trigger a service exhaust fluid system in a 2016 Duramax or any diesel car model.
Q: How do you reset the diesel exhaust fluid on a Chevy?
Resetting the DEF system in your Chevy is the best way to deal with the sudden trouble code on the dashboard. Here’s the process in a few steps: First, test the reductant fluid heater’s resistance with a multimeter (it should be between 2 and 4 Ohms).
After that, connect a scanner to the scan port beneath the vehicle’s dashboard on the driver’s side. Next, go to module setup > reductant fluid > tank level reset.
Then, engage the reset. After that, go back to the reductant system data reset and engage the reset too. Wait a while, and you’re done!
Q: How often should def fluid be changed?
Changing your diesel exhaust fluid (DEF) is determined by the amount of fuel your truck consumes.
The DEF fluid is consumed at around a 2% – 3% rate relative to the quantity of fuel you use. In other words, a truck using a 65-gallon tank will require up to 1.2 – 2 gallons of DEF fluid.
So, it is advisable to change your truck’s DEF fluid every 3rd to 4th time you refill the diesel fuel tank, especially if the truck runs on a 5-gallon DEF tank. This can help prevent service exhaust fluid system in a 2017 Duramax.
Q: Why does my truck say service exhaust fluid system?
If your truck’s dashboard is displaying a service exhaust fluid system, it simply means the DEF system has been tampered with. Therefore, the trouble code surfaces as a warning signal requiring a quick fix of the malfunction.
Ensure to rectify your truck’s DEF system if you ever come across this warning message at any point in time. Fixing the problem can be pretty easy.
Q: Will low DEF make the check engine light come on?
Not at all! Although various malfunctions can trigger a vehicle’s check engine light, low DEF may not directly trigger this signal. However, running on a low diesel exhaust fluid level puts your truck’s engine at a big risk.
If the fluid eventually runs out, it will reduce the engine power and immediately affect the vehicle’s speed level. In that case, a related fault may trigger the check engine light.
Ignoring the DEF system causes a malfunction and triggers the service exhaust fluid system in a 2019 Duramax or your respective car model.
Final Words
You shouldn’t panic because of the service exhaust fluid system warning signal. It is not the end of the road for your truck’s engine.
However, if you continue to defer resolving the service exhaust fluid system in your diesel truck, you may as well be playing with a potential engine disaster.
So, why not follow the recommendations in this article to fix the issue immediately? Nevertheless, ensuring that you never run out of diesel exhaust fluid will go a long way to protect your vehicle’s engine and enable it to reach its lifespan. So, this should be a priority.