The throttle body in your Chevy Silverado is responsible for allowing more air to enter your engine. Your Silverado TPS sensor is mounted to the shaft of the throttle body. This three pin sensor is what your Powertrain Control Module relies on to determine how far your throttle has opened. Based on the TPS signal your PCM then adjusts how much fuel to deliver to your Silverado engine.
When this sensor starts having problems, your truck engine will begin to run poorly. Some of these symptoms are obvious from the start, although many can be harder to diagnose. One of the first Chevy Silverado problems you’ll see is your check engine light turning on. If you see the Silverado check engine light on, you’ll need to use a OBDII scan tool to pull out the alphanumeric code.
Today I’ll be showing you how to test your Silverado TPS Sensor in a 2000 Chevy truck with a 5.3 liter Vortec engine in it. In order to use this DIY tutorial however, you’ll need to use a digital multimeter.
Before you begin it’s a good idea to plug your OBDII scan tool in to see what the trouble code is. If you find that it’s a TPS related issue, you can use this guide to test and replace it.
Because your Silverado TPS sensor requires calibration when replaced, this guide will also show you how to install the new part.
In order to test your Silverado TPS Sensor it’s a good idea to understand how it works. This sensor is basically a potentiometer, and it works by reading the angle of your throttle blade. As the throttle body is being opened, this sensor reads how far the throttle is opening and transmits this data.
The three wires that make up the TPS connector are power, ground and signal. We’ll begin this How To Guide by testing for power. Before we get into that however, let’s go over some of the common Chevy Silverado problems when your throttle sensor goes out.
Symptoms of a bad Silverado TPS Sensor
Depending on the severity of this failure, the throttle sensor can cause your engine to go haywire. Some of the more dangerous symptoms are the sensor sending false signals. There are many issues that can result from a failed or bad TPS sensor, here’s just a few of them below.
- Engine increasing speed on it’s own
- No throttle response
- Engine stalls
- Silverado won’t start
- Check Engine Light ON
If you have any of these Chevy Silverado issues and believe that your TPS sensor is to blame, we’ll begin by testing for power.
Testing your Silverado TPS Sensor for Power
To being working on your Silverado throttle sensor, you’ll need to turn the ignition to the “ON” position. This powers up the sensors in your engine bay, and now you can test your throttle position sensor. Now open your Silverado hood and locate the throttle sensor. It’s on the driver side of your throttle body, and you can disconnect it by lifting on the harness locking tab.
The wire you’ll be checking is the wire that leads to PIN C. This wire should be GRAY or GRAY with a RED stripe in it on the wiring harness. Don’t forget that you are testing the ENGINE harness side of the Silverado TPS sensor. When you test it with your voltmeter, never force the leads into the metal clips. Doing so may damage or compromise the contact quality of your TPS sensor.
With your Silverado ignition turned to the “ON” position, you should read 5 volts here. If you have power at this wire, the next wire to check is the wire that leads to PIN B.
This is the low reference signal, or the ground sent by your PCM. In order to check this you’ll basically be switching your multimeter leads around. Put the red lead to the positive terminal on your battery and gently touch the black lead to PIN B. This wire should be BLACK or BLACK with a pink stripe in it. If you have both power and ground at this sensor, the last step is to check the signal wire to make sure it’s working right.
Measuring a Silverado TPS Signal
If you have a OBDII trouble code for your TPS being out of range, or you are installing a replacement TPS, this part of the guide is for you. Once you are ready plug the Silverado TPS sensor harness back into the sensor. You will need to backpin the wire located at terminal A. If you don’t have a backpin handy, use the red lead of your multimeter and pierce this wire.
With the throttle plate closed you should be reading between .5 to .9 Volt DC of signal. This signal should not fluctuate but hold steady. This is what your Chevy PCM expects with your Silverado throttle completely closed.
Keep the ignition turned to the “ON” position and then manually open the throttle body. This position is known as Wide Open Throttle, and at the WOT position the Silverado TPS Sensor should transmit between 4.5 to 4.9 Volts of DC power.
If your Chevy throttle sensor does not respond with these values, chances are it’s gone out and needs to be replaced. When you are installing your replacement throttle sensor, you’ll need to calibrate your Silverado TPS Sensor for proper function.
This is a much cheaper way to fix your throttle body, rather than replacing the entire unit. When installing the replacement TPS sensor, you’ll need to adjust the sensor before tightening the set screws.
Have any questions about our How To guide on testing your Chevy Silverado throttle? Need more tech tips on your Silverado? Leave us a question or comment below and let us know!
