TPS TEST 2: Verifying TPS Has Power
The wire (circuit) labeled with the number 3 in the illustration is the one that feeds the TP sensor with power.
As stated earlier, this power is in the form of 5 Volts DC and is feed to the TP sensor by the PCM.
If your TP sensor did not show a variable voltage when you manually actuated the throttle in TPS TEST 1, then there's a good chance it's not being fed with power.
In this test section, we'll test for the presence of these 5 Volts using a multimeter.
NOTE: You can test for these 5 Volts DC with the TP sensor connected or disconnected to the TPS. I personally prefer to do this test with the TP sensor's connector unplugged.
You can see this test step performed in this YouTube video here: How To Test The TPS (1997, 1998, 1999, 2000, 2001 2.0L Honda CR-V) (NOTE: Although this video applies to the 1997-2001 2.0L Honda CR-V, the test procedure itself is the same for the 1996-2000 1.6L Honda Civic).
This is what you'll need to do:
- 1
Set your trusty multimeter's dial to Volts DC mode.
- 2
Probe the number 3 wire, with the red multimeter test lead and an appropriate tool (like a Wire-Piercing Probe). The throttle position sensor's connector can be connected to the sensor or not when you probe this circuit.
IMPORTANT If you probe the front of the TPS connector, be careful and don't damage the terminal. Damaging the terminal will require that you replace the connector. - 3
Connect the black multimeter test lead to a good and clean Ground point on the engine or directly on the negative (-) battery terminal.
- 4
When you've set up the test, have a helper turn the Key On Engine Off (KOEO).
- 5
Your multimeter should display 4.5 to 5 Volts on its screen. OK, now let's interpret your test results below:
CASE 1: The multimeter registered 4.5 to 5 Volts, this confirms that the TP sensor is being fed with power (4.5 to 5 Volts DC).
The next step is to test the Ground circuit of the throttle position sensor, go to: TPS TEST 3: Verifying TPS Has Ground.
CASE 2: Multimeter DID NOT register 4.5 to 5 Volts. Without this voltage the TP sensor will not function. The two most likely reasons for this are: 1) an open in the circuit (wire) or 2) the PCM may be fried (although a bad PCM is very rare).
Although it's beyond the scope of this article to test these two conditions, you have now eliminated the throttle position sensor (TPS) on your Honda as being the cause of the problem and/or the TPS diagnostic trouble code (DTC) lighting up the check engine light (CEL).
TPS TEST 3: Verifying TPS Has Ground
So far (if you've started from TEST 1) you've confirmed that the TP sensor isn't creating a variable signal and that it's getting power.
Now, we're gonna' check to see if it's getting Ground.
This Ground is provided by the wire labeled with the number 1, in the illustration in the image viewer.
IMPORTANT: Remember, the PCM is the one that provides this Ground internally so be careful and don't accidentally or intentionally apply power (12 Volts) to this circuit or you'll fry the PCM.
You can see this test step performed in this YouTube video here: How To Test The TPS (1997, 1998, 1999, 2000, 2001 2.0L Honda CR-V) (NOTE: Although this video applies to the 1997-2001 2.0L Honda CR-V, the test procedure itself is the same for the 1996-2000 1.6L Honda Civic).
OK, here are the test steps:
- 1
With your multimeter still in Volts DC mode from TPS TEST 2.
- 2
Probe the wire labeled with the number 1 in the photos with the black multimeter test lead. The TPS connector can be connected or not to the sensor.
It's important that you do not probe the front of the connector or you run the risk of damaging the terminal. - 3
Now, with the red multimeter test lead, probe the battery positive (+) terminal.
- 4
Once again, when everything is ready, have your helper turn the key to its ON position but don't start the engine.
- 5
If this circuit is OK and the PCM is providing a good path to Ground, your multimeter will display 11 to 12 Volts.
Let's take a look at your test results:
CASE 1: The multimeter showed 11 to 12 Volts. This confirms that the PCM and the wire/circuit (that supply this Ground) are OK.
All three test have confirmed that:
- The TPS is not providing a varying voltage signal when manually opening the throttle plate.
- The TPS is being fed 5 Volts DC.
- The TPS is being fed Ground.
Therefore, you can conclude that the TP Sensor is bad and needs to be replaced.
CASE 2: Multimeter DID NOT show 11 to 12 Volts. This usually indicates a problem with either the PCM (internal fault/problem) or an open in the wire between the TPS and the PCM itself.
Although testing these two conditions are beyond the scope of this article, you have now eliminated the throttle position sensor (TPS) on your Honda as being the cause of the problem and/or the TPS Diagnostic Trouble Code (DTC) lighting up the check engine light (CEL).
More 1.6L Honda Civic Test Tutorials
If this tutorial was helpful/informative, you can find a complete list of tutorials in this index:
Here's a sample of the tutorials you'll find there:
- How To Test For A Blown Head Gasket (Honda 1.6L).
- How To Test The Alternator (1996-2000 1.6L Honda Civic).
- Testing Shift Control Solenoid Valves A and B (1996-2000 1.6L Honda Civic).
- How To Troubleshoot A No Start (Honda 1.6L).
- How To Test The Igniter, Ignition Coil Accord, Civic, CRV, and Odyssey (at: easyautodiagnostics.com).
If this info saved the day, buy me a beer!
