How To Test The TPS Sensor (2000-2003 3.9L V6 Dodge Dakota)

TEST 2: Making Sure The TPS Has 5 Volts

In this section, we're gonna' make sure that the violet with white stripe (VIO/WHT) wire, of the throttle position sensor's 3-wire connector, is feeding the TPS with 5 Volts DC.

If these 5 Volts are missing, then the TPS will not function and not produce an increasing/decreasing voltage signal as you open/close the throttle plate.

We'll check for the presence of these 5 Volts by doing a simple multimeter voltage test on the VIO/WHT wire.

Let's get started:

1. 1

   Place your multimeter in Volts DC mode.

2. 2

   Disconnect the TPS from its electrical connector.

3. 3

   Turn the key the ON position but don't start the engine.

4. 4

   Connect the red multimeter test lead (using the appropriate tool) to the VIO/WHT wire.

5. 5

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

6. 6

   Your multimeter should read 4.5 to 5 Volts DC.

Let's analyze your test results:

CASE 1: The VIO/WHT wire has 5 Volts present. This is the correct test result.

The next and last test is to make sure the black with light blue stripe (BLK/LT BLU) wire is providing Ground to the throttle position sensor. Go to: TEST 3: Making Sure The TPS Has Ground.

CASE 2: 5 Volts are not present in the VIO/WHT wire. Without these 5 Volts the TPS will not function.

Although it's beyond the scope of this tutorial to troubleshoot these missing 5 Volts, the most likely cause is an open-circuit problem in the violet with white stripe (VIO/WHT) wire between the TPS sensor's connector and the fuel injection computer's connector.

TEST 3: Making Sure The TPS Has Ground

So far your test results have confirmed that:

• The TPS is not creating an increasing/decreasing voltage signal as the throttle plate is opened/closed (TEST 1).
• The TPS is getting 5 Volts on the violet with white stripe (VIO/WHT) wire (TEST 2).

Our last test is see if the black with light blue stripe (BLK/LT BLU) wire is feeding the throttle position sensor with Ground.

To check for the presence of Ground in the BLK/LT BLU wire we're gonna' do a simple multimeter voltage test (like the one we did in TEST 2).

NOTE: Ground is provided by your 3.9L Dodge Dakota's fuel injection computer. So be careful and do not apply battery power (12 Volts DC) to the Ground wire or you'll fry the computer. The voltage test I'm describing below (to test for Ground) is a safe way of verifying the presence of this Ground.

These are the test steps:

1. 1

   Place your multimeter in Volts DC mode.

2. 2

   Disconnect the TPS from its electrical connector.

3. 3

   Turn the key the ON position but don't start the engine.

4. 4

   Connect the black multimeter test lead (using the appropriate tool) to the BLK/LT BLU wire.

5. 5

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

6. 6

   Your multimeter should read 10 to 12 Volts DC.

Let's analyze your test results:

CASE 1: Ground is present in the BLK/LT BLU wire. This is the correct and expected test result.

You can conclude that the your Dodge Dakota's throttle position sensor is defective if you have:

• Confirmed that the TPS voltage signal does not increase/decrease as you opened/closed the throttle plate (TEST 1).
• Confirmed that the TPS is getting 5 Volts on the VIO/WHT wire (TEST 2).
• Confirmed that the TPS is getting Ground on the BLK/LT BLU wire (this test).

If you need to buy the TPS, check out my recommendations here: Where To Buy The TPS And Save.

CASE 2: The BLK/LT BLU wire IS NOT feeding the TPS with Ground. Without Ground the TPS will not function.

Although it's beyond the scope of this tutorial to troubleshoot this missing Ground, the most likely cause is an open-circuit problem in the BLK/LT BLU wire between the throttle position sensor's connector and the fuel injection computer's connector.

More 3.9L Dodge Dakota Tutorials

You can find a complete list of 3.9L V6 Dodge Dakota tutorials in this index:

• Chrysler 3.9L Index Of Articles.

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

• How To Test The Starter Motor (1991-1995 3.9L Dodge Dakota).
• How To Test Engine Compression (1993-2003 3.9L Dodge Dakota).
• How To Test For A Blown Head Gasket (1993-2003 3.9L Dodge Dakota).
• Engine Management Sensor Circuit Diagram (1994-1995 3.9L V6 Dodge Dakota).