Read & Repair: Throttle Position Sensors

- by Ryan Kooiman

Our “Read & Repair” series gives you background information about a particular part as well as tips to help with the job. Today’s topic is throttle position sensors. Let's get started.

How Do Throttle Position Sensors (TPS) Work?

TPS SchematicMost throttle position sensors (TPS) are 3 wire potentiometers. They have a power supply (typically 5 volts), a ground, and a signal return wire. Inside the TPS is a mechanical arm that’s attached to the shaft that holds the throttle blade. As the throttle moves, the arm makes contact at various points on a resistor strip. The correlating voltage is then sent through the signal line to the Powertrain Control Module. Newer TPS use a non-contact method and Hall effect-type sensors.

It’s important to note that proper adjustment of the TPS is critical. A misadjusted TPS will result in poor idle, stalling, lack of power, and improper transmission shifting, just to name a few issues.

The Trouble with Honda and Acura Throttle Position Sensors

Traditionally, throttle position sensor replacements are straightforward jobs: you remove the two mounting screws, install and adjust the new sensor, tighten down the screws, and the job is done. Some manufacturers such as Honda and Acura, however, rivet the throttle position sensor to the throttle body. As a result, when the TPS fails, you need to purchase a complete throttle body assembly.  

So How Do You Remove Faulty TPS on Those Hondas and Acuras?

1. Drill out the rivets. Note: You may need to remove the throttle body for access. Also, don’t use an oversized bit. Otherwise, you risk making the hole bigger than it originally was.

2. Once you remove the old unit, install the new throttle position sensor and attach it to the throttle body. TechSmart’s Throttle Position Sensor Repair Kits come complete with a gasket and mounting hardware, including screws that have hardened threads that cut into the aluminum throttle body.

3. Refer to service information to find the proper specs for the vehicle. Generally speaking, most throttle position sensors will read approximately 0.5 volt at closed throttle and 4.5 volts at wide open throttle.  You can verify the reading by using a scan tool or a voltmeter.  

Kooiman 3 Ryan Kooiman is the Director of Training at Standard Motor Products. In addition to leading SMP's award-winning PTS training program, he is the face of SMP's 'Installation Spotlight' videos on YouTube. He has ASE Master L1, L2, and L3 Certifications, and has had articles published in over 30 periodicals.