How To Reset Check Engine Light on Peterbilt 579, Peterbilt truck

How To Reset Check Engine Light on Peterbilt 579

I also faced the check engine light situation in my Peterbilt 579. After deep research, I was able to fix the check engine light on the Peterbilt by myself. So, how to reset check engine light on Peterbilt 579

To reset the check engine light on Peterbilt 579, ensure the truck is stationary. Turn the key to the “On” position without starting the engine, turn off all accessories, and then turn the key back to the “Off” position. Repeat the on/off cycle rapidly, and the check engine light should turn off, indicating a successful reset.

In this article, I will explain important things I gathered in my research and how to reset check engine light on Peterbilt 579 as a step-by-step guide.

Pros and Cons of Peterbilt 579

Peterbilt truck

Here are the main positives and negatives of the Peterbilt 579 according to user reviews. You might already know these.

Multiple power outletsSwitches and controls are spread out
Good visibilityLimited storage options
Heated mirrorsUpper bunk design
Cummins engineManual turn signal cancellation
No air release fifth wheel
Fuel economy could be better
CB antenna placement


Positives in detail

Multiple Power Outlets

The truck has numerous power outlets, including USB ports and 12-volt outlets. They are useful for charging various devices and powering accessories.

Good Visibility

The mirrors on the truck offer excellent visibility. The single-piece wrap-around windshield provides a clear field of view.

Heated Mirrors

The heated mirrors help melt ice and snow quickly during cold weather conditions.

Cummins Engine

While it is mentioned that the Cummins engine is loud, it still provides decent power and performance.


As with every vehicle, the Peterbilt also has some negatives.

Switch Placement

The switches and controls in the truck are spread out and not consolidated, making it less convenient to access them while driving.

Limited Storage

The storage options in the truck, particularly for personal belongings, are not well designed. The available spaces are small and not organized. This can be frustrating for those who prefer a more organized setup.

Upper Bunk Design

The upper bunk is described as folding in half and having a thin mattress. It potentially leads to discomfort for the person using it.

Lack of Automatic Turn Signal Cancellation

The turn signals need to be manually canceled, which can be inconvenient. It may cause you to forget to turn them off.

No Air Release Fifth Wheel

The truck does not have an air-release fifth wheel for uncoupling the trailer, requiring manual effort and making the process less efficient.

Fuel Economy

The fuel economy of the Cummins X15 Efficiency Series engine is mentioned to be in the high sixes, which is not as good as some other trucks in its class.

CB Antenna Placement

The CB antenna is positioned behind the fairing on the back of the truck. This is causing potential signal issues when driving away from someone because the trailer blocks the antenna.

How To Reset Check Engine Light on Peterbilt 579

Peterbilt dashboard all lights on

One day, I parked the truck in the garage. Before turning off the truck, I looked at the dashboard. Then, I suddenly noticed the check engine light had come on. The question that suddenly came to mind was why this came on and how to reset check engine light on Peterbilt 579.

There was no noticeable engine or transmission problem in my Peterbilt. So, I did thorough research to find a way to reset the check engine light. I tried various methods, and they were all unsuccessful. Finally, I was able to find a way to do the task.

Here is how to reset check engine light on Peterbilt 579 easily and successfully.

Step 1

First, I ensured the truck was in a safe and stationary position.

Step 2

Then, I turned the ignition key to the “On” position without starting the engine. This is the position where the dashboard lights come on.

Step 3

I made sure that all accessories such as the cruise control, engine brake, and air conditioner, were turned off. This step was important to ensure a successful reset.

Step 4

Next, I turned the key back to the “Off” position.

Step 5

Then I repeated steps 2 and 4 (turning the key on and off) five or six times within a span of five or six seconds. This rapid cycling of the key was done to reset the check engine light.

Step 6

I observed the check engine light on the dashboard. It turned off after a few moments, indicating that the reset process was successful.

Note: If the check engine light came back on after resetting, it could indicate an underlying issue that required attention. In such cases, I recommend you have the truck inspected by a qualified mechanic to diagnose and resolve any potential problems.

What Are the Common Causes of The Check Engine Light on Peterbilt 579?

  1. Faulty Oxygen Sensor: The oxygen sensor measures the amount of oxygen in the exhaust system. When the oxygen sensor malfunctions, the check engine light triggers.
  2. Loose or Faulty Gas Cap: If the gas cap is loose, damaged, or not sealing properly, it causes the check engine light.
  3. Malfunctioning Mass Airflow Sensor: A faulty sensor can cause an improper air-fuel mixture, leading to decreased performance and fuel efficiency.
  4. Emission Control System Issues: Problems with components such as the catalytic converter, evaporative emissions system, or exhaust gas recirculation (EGR) system can trigger the check engine light.
  5. Ignition System Problems: Issues with spark plugs, ignition coils, or the ignition control module can lead to misfires or rough engine performance and check engine light.
  6. Malfunctioning Throttle Position Sensor: The throttle position sensor monitors the position of the throttle and communicates it to the engine control unit. A faulty sensor is represented by a check engine light.
  7. Exhaust Gas Recirculation (EGR) Valve: carbon buildup or valve failure, cause of the check engine light on the Peterbilt 579.
  8. Transmission Issues: Faulty sensors, solenoids, or other components in the transmission system are the causes of the check engine light.


Is the Peterbilt 579 automatic?

Yes, the Peterbilt 579 has a PACCAR MX 12-speed automated transmission engine.

How often do you change Peterbilt oil?

A Peterbilt oil change should be done between 7,500 and 10,000 miles.

Which Peterbilt is the aerodynamically best?

The new vehicle 579 is the most aerodynamic and fuel-efficient Peterbilt vehicle produced to date, with an increase in fuel efficiency of 7% over previous generation models.

How many miles can a Peterbilt last?

A typical Peterbilt vehicle has a lifespan of up to or exceeding 750,000 kilometers. An average semi-truck covers 45,000 kilometers a year. An average semi-truck covers 45,000 kilometers a year. Even vehicles have reached the million-mile milestone!


The check engine light on a Peterbilt 579 is a cause for concern, but it is possible to reset it without the need for professional assistance. I hope you understand how to reset check engine light on Peterbilt 579.

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