The throttle position sensor can be easily tested using only a multimeter and in this article, I'll show you how.
This article covers troubleshooting diagnostic trouble codes (DTCs) P0121, P0122, P0123 on Dodge 3.9L, 5.2L and 5.9L pick ups, vans and SUVs.
NOTE: This tutorial only covers the throttle position sensor on late 1997 thru' 2003 Ram pickups/vans. For early 1997 thru' 1994 Ram pickups/vans, see the following tutorial:
The throttle position test is divided into several parts, and so... to help you navigate this article, here are the contents of this article at a quick glance:
The following wiring diagram article may come in handy:
You'll have the CHECK ENGINE LIGHT on your instrument cluster shining nice and bright for sure.
You'll also experience one or several of the following symptoms:
The throttle position sensor's job is to measure the angle of the throttle. So here, in a nutshell, is how the throttle position sensor works when you crank and start your 3.9L, 5.2L, 5.9L Dodge:
Pretty easy stuff? The cool thing is that the tests to check out the TP sensor's performance are as easy too. Since testing the TPS simply involves making sure that the sensor is creating a throttle angle voltage signal (which can be verified with a multimeter in Volts DC mode).
If the TP sensor is not creating a voltage signal, then the next steps are to make sure that it's getting power and ground from the PCM. These two things you can also verify with your multimeter.
IMPORTANT: Since you'll be working in the engine compartment take all necessary safety precautions and use common sense.
“For instance, on the planet Earth, man had always assumed that he was more
intelligent than dolphins because he had achieved so much —the wheel,
New York, wars and so on —whilst all the dolphins had ever done was
muck about in the water having a good time. But conversely,
the dolphins had always believed that they were far more
intelligent than man —for precisely the same reasons!”
The Hitchhiker's Guide to the Galaxy