The three pin RSX TPS sensor in your 2.0 liter DOHC K series Acura is designed to read the angle of your RSX throttle blade. This sensor is mounted opposite of your throttle blade and cable, and works as a basic potentiometer. Your throttle sensor is mounted to the K20 throttle shaft and as your throttle body opens this sensor reads how far the throttle is being opened.
Your Acura RSX ECU uses this data to properly deliver the right amount of fuel. When this TPS sensor goes bad, your engine computer won’t know how to control your DOHC fuel curves. The problems that are caused from your Acura RSX TPS sensor going bad can lead to issues with your fuel curves or you may find your Acura RSX won’t start.
Today I’ll be showing you how to test your RSX TPS sensor in a 2003 Acura. In order to complete this test correctly you will need to use a digital multimeter. You will be testing the wiring harness that leads to your Acura RSX TPS sensor to determine whether or not your throttle sensor is working correctly.
When your OBDII RSX check engine light is turned on, you’ll need a scan tool to read the trouble codes.
If your RSX check engine light comes back as a TPS related failure, you’ll need this guide to test your throttle sensor.
Some of the more obvious throttle position sensor trouble codes include P0122 Throttle Position Sensor/Switch A Circuit Failure. When your K20 RSX is showing this error, you’ll need to use this DIY guide to testing your RSX TPS sensor.
To begin open your hood and locate the throttle sensor. This sensor is located near your firewall and mounted opposite of your throttle cable.
This powers up the sensors in your K20 engine. Now disconnect the Acura RSX TPS sensor harness.
The first wire we’ll be starting with is the power wire. Refer to our Acura RSX TPS sensor wiring diagram below to see what wires you’ll be testing on the ENGINE side of the throttle sensor.
Once you have the throttle sensor unplugged, you’ll be using your multimeter to check for power.
The wire that leads to PIN 3 is the VCC2 wire. This wire should be transmitting 5 volts of switched power with your ignition turned to the ON position.
This wire is a YELLOW wire with a BLUE stripe in it. If you have power here the next wire to check is the SG2 wire at PIN 1, which should be a GREEN wire with a YELLOW stripe in it. This should have a ground signal for your RSX TPS Sensor.
If you have power and ground at these wires, the next part of this guide is to check the Acura RSX TPS sensor signal.
Test the Acura RSX TPS sensor signal wire
The next part of this guide will show you how to test the RSX TPS sensor signal. Connect the black lead of your multimeter to the negative battery terminal, and reconnect the TPS harness. Now pierce the wire that leads to PIN 2 with the red lead of your multimeter.
With your throttle in the closed position, this wire should read between .5 and .9 volts of signal. Now manually open your throttle body until it’s fully open. Monitor the voltage at PIN 2, it should sweep slowly and smoothly until it stops between 3.9 and 4.5 volts of DC signal.
Now you can test the RSX TPS sensor by testing at the sensor itself. This part of the test will require you to unplug the RSX throttle sensor again.
There should be between 0.5 and 0.9 kΩ at these two wires. If this part of the test checks out, now connect your multimeter leads at PIN 1 and PIN 2.
With the throttle plate closed there should be around 4.5kΩ at these two wires. If your RSX TPS sensor does not respond in the following fashion you will need to remove and install a replacement throttle sensor.
You will need to calibrate the throttle position sensor once you’ve installed it for proper operation. Have any questions about our RSX TPS sensor testing guide? Leave them for us below and let us know!