TEST 2: Checking Throttle Position Sensor (TPS) Power And Ground
If you've reached this point in your diagnostic test of the TPS, then the sensor has not produced a voltage signal that increases or decreases as you open and close the throttle plate manually.
The next step, to be able to definitely say that the TPS is fried, is to make sure that it's getting both power (5 Volts) and Ground.
The YEL/BLU wire, of the TP sensor harness connector, is the one that provides the 5 Volts to the TPS and the GRN/YEL wire is the one that provides Ground.
With the multimeter if Volts DC mode, this is what you need to do:
- 1
Check terminal #1 for power with the Key On Engine Off (KOEO) (see illustration above).
Back probe terminal number 1 with the red multimeter test lead and connect the black lead to the battery negative (-) post.
The YEL/BLU wire connects to terminal number 1 of the TP sensor harness connector.
The multimeter should register 4.5 to 5 Volts DC. - 2
Check terminal #3 for Ground with the Key On Engine Off (KOEO) (see illustration above).
Back probe terminal #3 with the black multimeter test lead and connect the red lead to the battery positive (+) post.
The GRN/YEL wire connects to terminal number 3 of the TP sensor harness connector.
The multimeter should register battery voltage (12+ Volts).
CASE 1: Both Ground and power (5 Volts) are present. This is the correct and expected test result.
Since you have now confirmed (in TEST 1) that the TP sensor is not producing a signal and in this test you've confirmed that the sensor is getting both power and Ground, you can conclude the TP sensor is bad and needs to be replaced.
CASE 2: Either Ground or power ARE NOT present. This test result exonerates the TP sensor as being bad and tells you that the reason the TP sensor is not producing an increasing/decreasing voltage signal in TEST 1 is because it's missing power or Ground.
Although it's beyond the scope of this tutorial, you'll need to find out why this signal is missing to get the TP sensor back on the job.
Where To Buy The Throttle Position Sensor
The aftermarket throttle position sensors that will fit your 1.7 liter Honda Civic are the: Dorman 977-022 Throttle Position Sensor and the Standard Motor Products T42005 Throttle Position Sensor.
The following links will help you to comparison shop for the Dorman and Stander throttle position sensor on your 1.7L Honda Civic:
Not sure if the throttle position sensor listed above fits your particular 1.7 liter Honda Civic? Don't worry, once you get to the site they are going to ask you the specifics of your vehicle to make sure it fits. If it doesn't fit, they'll find you the right one.
If this info saved the day, buy me a beer!
