How To Test The TPS (2000-2002 1.8L Sentra)

TEST 2: Making Sure The TPS Is Getting 5 Volts

If your TP sensor test results in TEST 1 indicated a TPS voltage signal that DID NOT increase/decrease when opening/closing the throttle plate, the next step is to verify that it's getting 5 Volts.

In this section, we'll verify that the fuel injection computer is providing power in the form of 5 Volts DC to the TP sensor.

The red (RED) wire of the brown connector supplies 5 Volts to the sensor.

IMPORTANT: The PCM is the one that feeds this Ground to the throttle position sensor (TPS). Be careful not to short this wire to battery voltage or you will fry the PCM.

This is what you need to do:

1. 1

   Select Volts DC mode on your multimeter.

2. 2

   Turn the key to its ON position but don't crank or start the engine.

3. 3

   Disconnect the brown connector from the TP sensor assembly.

4. 4

   With the red multimeter test lead probe the red wire of the brown connector.
   
   NOTE: If you probe the front of the female terminal with your multimeter test lead, be careful not to damage it.

5. 5

   Connect the black multimeter test lead to the negative (-) battery terminal.

6. 6

   The multimeter should report 4.5 to 5 Volts DC.

Let's take a look at what your test results mean:

CASE 1: 5 Volts DC are present. This is the correct and expected test result.

Your next step is to see if the TPS is getting Ground. Go to: Making Sure The TPS Is Getting Ground.

CASE 2: 5 Volts DC are NOT present. Double check that you're testing the correct wire and repeat the test.

If your multimeter still doesn't read the indicated voltage, you can conclude that the TPS is not getting power.

You can also conclude that the wire between the TP sensor harness connector and the PCM harness connector probably has an open-circuit problem. In extreme cases, the PCM has an internal problem (although this is very rare).

Although testing for an open-circuit problem in the wire is beyond the scope of this article, you now know that the throttle position sensor itself is not the cause of the problem illuminating the Check Engine Light (CEL) with a TPS trouble code.

TEST 3: Making Sure The TPS Is Getting Ground

So far, the previous two tests have confirmed the following:

• The TPS signal does not increase/decrease when you open/close the throttle plate (TEST 1).
• The TPS is getting 5 Volts (TEST 2).

The focus of this final test section is to check that the throttle position sensor is receiving Ground.

The wire that delivers Ground to the TPS is the black (BLK) wire of the 3-wire connector.

A simple voltage test with a multimeter will suffice to check for the presence of Ground in this black wire.

Let's get going:

1. 1

   Select Volts DC mode on your multimeter.

2. 2

   Turn the key to its ON position but don't crank or start the engine.

3. 3

   Disconnect the brown connector from the TP sensor assembly.

4. 4

   With the black multimeter test lead probe the black wire of the brown connector.
   
   NOTE: If you probe the front of the female terminal with your multimeter test lead, be careful not to damage it.

5. 5

   Connect the red multimeter test lead to the positive (+) battery terminal.

6. 6

   The multimeter should report 10 to 12 Volts DC.

Let's take a look at what your test results mean:

CASE 1: The multimeter registered 10 to 12 Volts. This is the correct and expected test result.

You can conclude the TPS is bad if you have:

• Confirmed the TPS signal voltage does not increase/decrease as you open/close the throttle plate (TEST 1).
• Confirmed the red wire is delivering 4.5 to 5 Volts (TEST 2).
• Confirmed the black wire is delivering Ground to the sensor (this test section).

CASE 2: The multimeter DID NOT register 10 to 12 Volts. Double check that you're testing the correct wire and repeat the test.

If your multimeter still doesn't read the indicated voltage, you can conclude that the TPS is not getting Ground.

You can also conclude that the wire between the TP sensor harness connector and the PCM harness connector probably has an open-circuit problem. In extreme cases, the PCM has an internal problem (although this is very rare).

Although testing for an open-circuit problem in the wire is beyond the scope of this article, you now know that the throttle position sensor itself is not the cause of the problem illuminating the Check Engine Light (CEL) with a TPS trouble code.

More 1.8L Nissan Sentra Tutorials

You can find a complete list of tutorials for you Nissan 1.8L equipped car here: Nissan 1.8L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• How To Test The Ignition Coils (2000-2006 1.8L Nissan Sentra).
• How To Test The Starter Motor (2000-2002 1.8L Nissan Sentra).
• How To Test Engine Compression (2000-2006 1.8L Nissan Sentra).
• How To Test The 2000-2002 Nissan Sentra 1.8L MAF Sensor (at: easyautodiagnostics.com).