How to Check the TPS Voltage on a Chevy Truck

by Russell Wood
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The TPS on a Chevrolet truck is the throttle position sensor. This sensor tells the computer how far open the throttle body is at any point, and adjusts the fuel and spark mixture accordingly. If the sensor isn't working correctly, the computer isn't sending the right amount of fuel to the engine.

Step 1

Open the hood on the truck. Remove the engine's air cleaner by removing the wingnuts. Locate the TPS sensor on the passenger side of the throttle body. Unplug the harness connected to the TPS sensor.

Step 2

Place the black probe from the voltmeter on the middle terminal inside the TPS. Place the voltmeter's red probe on the the top, rearward terminal of the TPS.

Step 3

Put the key in the ignition. Turn the key to the "on" position, but do not start the engine.

Step 4

Look at the voltmeter. The voltage should read between 0.5 and 1.2 volts when the throttle body is closed. Turn the throttle linkage by hand, opening and closing the throttle body. Watch the voltmeter to ensure voltage moves up and down in conjunction with the movement of the throttle body. The TPS sensor must be replaced if the voltmeter spikes.

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