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Dodge Ram: How to Reset PCM and Check Engine Light

Just made some change to your Dodge Ram and the check engine light is still on? Whatever the reasons, this article will show you how to reset your truck's computer and check engine light.

By Jared Hammond - July 20, 2015

This article applies to the Dodge Ram 2nd, 3rd, and 4th Generation (1994-Present).

It's not uncommon for a check engine light to remain lit long after the issue setting it off in the first place has been fixed. To make it go away, you have to reset the powertrain control module (PCM), which among its many jobs is also in charge of the check engine light. There are other reasons why you would need to reset the PCM, such as after the installation of aftermarket components that require a PCM reset so the truck can fully adjust to new components. The reset procedure in your Dodge Ram is as easy as they come.

Step 1 – Remove the PCM fuse

First, park your truck and turn it off. Pull the hood lever under the driver's side dash, and then pull the safety catch on the front of the hood to open it. Find the power distribution center (PDC); it will be a black box near the battery. Unlatch and open the cover of the PDC. Take a look at the diagram on the back of the cover. Identify the fuse for the PCM. Depending on your Ram truck model, it will either be fuse #19, #23, or #31. Pull the fuse from the PDC.

Figure 1. The inside of the cover should look something like this.

Step 2 – Reset the PCM

Get in the driver's side of the truck, shut the door, and put on your seat belt. You'll need to listen for chimes when you're resetting the PCM, and having the door open and seat belt off will set off some warning chimes that will make this more difficult. First, put your key in the ignition and turn it on so the dash lights come on and the chimes start, but don't start the engine. Wait and listen for two quick chimes that will confirm that the PCM has been reset, then shut off the truck and take the key out.

Figure 2. With the key in the ignition, turn it to the first notch.

Step 3 – Re-install the PCM fuse

Reverse the actions of the first step by plugging the PCM fuse back into the PDC. Go back and start the truck to make sure that the check engine light has been shut off. If it didn't work, try again. Once you've got it to work, put back the cover for the PDC and close the hood of your truck.

Pro Tip

If you're not having much luck with this method, you can also disconnect the battery for 30 seconds. This should force the PCM to reset, but you'll also reset your radio clock and stations.

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