When you’ve got a OBDII check engine code for any throttle sensor related failure in a GMC, this guide can help you test your Sonoma TPS sensor. This sensor is a potentiometer that’s installed into the opposite end of your throttle blade and wire, and reads the position of your throttle body. The angle is then translated into a signal and transmitted to your GMC engine computer.
Your GMC engine computer needs this data to deliver the right amount of fuel. Without this data there’s no way your engine will run quite right. You idle can suffer and your engine could run lean ( not enough fuel ) which can lead to premature engine failure.
This throttle position sensor carries a GM part number of #17106809. If your local Chevy or GMC dealership doesn’t have this part available, try a few interchange numbers such as 17113578 or 17123852 both qualify.
Today I’ll be showing you how to test a throttle position sensor in your 2.2 liter 4 cylinder Sonoma truck. This sensor is mounted to your throttle body by way of two bolts, and can easily be replaced with hand tools. However to test your Sonoma TPS sensor and to install a new one, you’ll need to use a digital multimeter to dial in the signal voltage.
This throttle position sensor is a three pin unit that’s triangular in shape. I will be showing you how to test the Sonoma TPS sensor at both the sensor as well as the engine harness. When your throttle sensor in your 2.2 liter GMC engine goes bad, there’s a few symptoms you’ll see in your Sonoma truck.
Symptoms of a bad Sonoma TPS sensor
When the throttle sensor in your 2.2 liter engine goes out, the engine computer won’t know what is really going on. This can lead to imbalance to your air fuel ratio, which can cause some serious issues either way.
- Bad gas mileage
- poor performane
- inconsistent throttle response
- Engine revs or increases speed automatically
- Check Engine Light ON
If your TPS goes bad, there’s a good chance that your Sonoma may run rich. This means there’s too much fuel in your air fuel mixture, which can burn out or lead to catalytic converter failure. This is caused by the excessive hydrocarbons in your exhaust stream. Your 2.2 liter engine could also run lean, which means not enough fuel which will lead to pre-detonation and engine failure.
Testing your Sonoma TPS sensor for Power
In order to test your throttle sensor in your 2.2 liter GMC engine, you’ll need to use a digital multimeter. Not sure what that really is? check it out with this article here. You’ll need to locate your Sonoma TPS sensor before you can begin this tutorial.
Where is my GMC Sonoma TPS sensor?
The intake tract for your 2.2 liter GMC Sonoma leads to your throttle body, which is pointed upwards in your engine bay. The TPS sensor is installed into the side of your throttle body, and connected by way of a three pin triangular engine harness. Once you’ve found your TPS sensor, start your engine and allow it to warm up first.
Once your 2.2 liter engine has warmed up, disconnect the harness from your Sonoma TPS sensor. Now using your multimeter you’ll need to test for power at PIN B. Reference the Sonoma TPS sensor wiring schematic below to check for this wire. Remember that you are checking on the ENGINE harness side, which is the RED wire.
You should have around 5 volts of DC power here at this wire. If you don’t make sure your Sonoma ignition is turned to the “ON” position. Now that you know you are getting power, it’s time to check for a ground signal. This is located at PIN B on the ENGINE harness side of your Sonoma TPS sensor.
If you’ve got both power and ground at these two wires, but your Sonoma TPS sensor is still not responding or your OBDII check engine light is still lit, it’s time to check the signal wire. This is located at PIN B or WIRE 3 as shown above on the Sonoma TPS sensor wiring guide.
This wire is BLUE in color and leads directly out to your engine harness. You will need to reconnect the Sonoma TPS sensor in order to test for signal. Once the harness is reconnected, pierce the BLUE wire with the red multimeter lead. With the key turned to ON, this wire should read between .5 to .8 volts of DC power with the throttle body closed.
Now you can manually open the throttle body or the throttle plate with your hand. Deflect the throttle body opening until it’s at WOT or Wide Open Throttle. At this throttle blade position the BLUE wire should measure the voltage between 4.5 to 4.9 volts.
If your Sonoma TPS sensor doesn’t return these values during your test or once you’ve completed our How To tutorial, you need a replacement throttle sensor. Replace your sensor by bolting on the new unit and then measure the signal range until you’ve properly calibrated the throttle.
Have any questions about this Sonoma TPS sensor guide? Leave us a comment below and let us know!
