How To Test The TPS (1993-1995 2.5L SOHC Dodge Dakota)

TEST 2: Checking Throttle Position Sensor (TPS) Power And Ground

Making sure that the throttle position sensor is getting both power and Ground is a very important diagnostic test step in determining if the sensor is defective (or not).

The two wires that we need to test are the violet with white stripe (VIO/WHT) wire and black with light blue stripe (BLK/LT BLU) wire of the throttle position sensor connector.

The VIO/WHT wire is the one that feeds 5 Volts to the throttle position sensor and the BLK/LT BLU wire is the one that feeds Ground to it.

IMPORTANT: You need to be very careful not to short the Ground wire to battery power or you will fry the fuel injection computer on your 2.5L Dodge Dakota.

This is what you need to do:

1. 1

   Check the VIO/WHT wire for power with the Key On Engine Off (KOEO) (see illustration above).
   
   Back probe the TP sensor's engine wiring harness connector with the red multimeter test lead and connect the black lead to the battery negative (-) post.
   
   The multimeter should register 4.5 to 5 Volts DC.

2. 2

   Check the BLK/LT BLU wire for Ground with the Key On Engine Off (KOEO) (see illustration above).
   
   Back probe the TP sensor's engine wiring harness connector with the black multimeter test lead and connect the red lead to the battery positive (+) post.
   
   The multimeter should register battery voltage (12+ Volts).

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

CASE 1: Both Ground and power (5 Volts) are present. This is the correct and expected test result.

Now that you have confirmed that the throttle position sensor is getting both power and Ground and that it is not producing and increasing/decreasing voltage signal (TEST 1), you can conclude that the throttle position sensor is defective and needs to be replaced.

CASE 2: Either Ground or power ARE NOT present. This test result lets you know that the TP sensor is not producing an increasing/decreasing voltage signal due to the fact that it is not getting power and/or Ground.

This is usually caused by a problem in the wiring between the TP sensor connector and the fuel injection computer's connector. Although it's beyond the scope of this tutorial to diagnose this specific type of problem, your next step should be to check the continuity of the wiring between the TP sensor connector and the fuel injection computer's connector.

Where To Buy The Throttle Position Sensor

The throttle position sensor for your 2.5L SOHC Dodge Dakota isn't an expensive component. As a matter fact, it's a component that you can find just about at any auto parts store. Check out the following links and comparison shop, I think I'll save you a few bucks on your TP sensor purchase.:

Not sure if the throttle position sensor listed above fits your particular 2.5L Dodge Dakota? 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.