What is causing reduced engine power?

Good to hear, please use 2CarPros anytime we are here to help.

Welcome to 2CarPros.

First, you really should have the computer scanned to identify diagnostic trouble codes. Here is a quick video showing how it is done:

https://youtu.be/YV3TRZwer8k

I realize most people don't own one, but often times parts stores will do it for you free of charge or rent / lend you the tool.

Next, most often, the light is triggered by a bad wheel speed sensor or even low brake fluid.

Here is a link that shows how to check wheel speed sensors:

https://www.2carpros.com/articles/abs-wheel-speed-sensor-test

I don't know if you need them, but here are a couple links that you may find helpful when checking the sensors:

https://www.2carpros.com/articles/how-to-use-a-voltmeter

https://www.2carpros.com/articles/how-to-check-wiring

__________________________________

If you find one of the sensors is bad, directions for front sensor replacement are listed in pictures 1 and 2

Pictures 3 and 4 are related to rear sensor replacement.

__________________________________

Let me know what you find. Also, and don't laugh, make sure the brake fluid is full.

I will watch for your reply.

Joe

The fly by wire system has a failure. It could be the throttle body or the pedal sensor. It needs to be checked by a shop to confirm the failure

Roy

No, that's a lot more technical than that. Your truck is equipped with a "drive by wire" throttle system that uses redundant sensors to read throttle position and if the computer detects a problem in any one of them, it limits the truck to half throttle. You need a shop that is well versed in diagnostics and has an updated professional scan tool that can interface with these controls.