TEST 2: Verifying MAP Sensor Has 5 Volts And Ground
As I mentioned in the previous test section, to confirm that the MAP sensor is defective, we need to make sure that it's getting both power and Ground.
The fuel injection computer on your 2.5L Dodge Dakota is the component that supplies this power and Ground to the MAP sensor.
The MAP sensor gets power across the violet with white stripe (VIO/WHT) wire and gets Ground across the black with light blue stripe (BLK/LT BLU) wire of the MAP sensor's engine wiring harness connector.
We can confirm the presence of both of these by doing a simple multimeter voltage test.
IMPORTANT: When testing the Ground wire of the MAP sensor connector, be careful not to short it to 12 Volts (battery power) or you will fry your 2.5L Dodge Dakota's fuel injection computer.
Set your multimeter to Volts DC and:
- 1
Verify that the VIO/WHT wire has voltage (4.5 to 5 Volts DC) with the key on but engine off.
Connect the red multimeter test lead (using the appropriate tool) to the VIO/WHT wire. Connect the black multimeter test lead to the negative battery terminal.
Your multimeter should read 4.5 to 5 Volts DC. - 2
Verify that the BLK/LT BLU wire has Ground with the key on but engine off.
Connect the black multimeter test lead (using the appropriate tool) to the BLK/LT BLU wire. Connect the red multimeter test lead to the positive battery terminal.
Your multimeter should read 12 Volts DC.
Let's take a look at your test results:
CASE 1: The multimeter confirms that the MAP sensor is being fed power and Ground. This is the correct and expected test result.
With this test result you can now conclude that the MAP sensor is defective and that it needs to be replaced. To be a bit more specific, you can reach this conclusion because you have confirmed that the MAP sensor is getting power and Ground and yet it's not producing decreasing increasing voltage signal when you applied vacuum (in TEST 1).
CASE 2: Multimeter confirms that the MAP sensor IS NOT being fed power or Ground. This test result tells you that the reason the map voltage signal did not react to the vacuum you applied (in TEST 1) is because it's missing power and/or Ground.
The most common cause of this test result is a problem in the wiring between the MAP sensor connector and the fuel injection computer connector. Although it's beyond the scope of this tutorial to check the MAP sensor wiring, your next steps should be to check the continuity of the MAP sensor circuits between its connector and the fuel injection computer connector.
Where To Buy The MAP Sensor And Save
The MAP sensor isn't an expensive engine management component, but it never hurts to save a few bucks and so with that in mind I think that the following links will help you to comparison shop for it and maybe even save a few bucks:
NOTE: If you're not sure if the above MAP sensor fit your particular 2.5L Dodge Dakota don't worry, once you get to the site, they'll make sure the sensor is the right one, if not, they'll find you the right one.
More 2.5L Dodge Dakota Tutorials
You can find a complete list of tutorials here: Chrysler 2.5L 4-Cylinder Index Of Articles.
Here's a sample of the tutorials you'll find there:
- Oxygen Sensor Heater Test (1993-1995 2.5L Dodge Dakota).
- How To Test The TPS (1993-1995 2.5L SOHC Dodge Dakota).
- How To Test For A Blown Head Gasket (1993-2002 2.5L Dodge Dakota).
- How To Test Engine Compression (1993-2002 2.5L Dodge Dakota).
If this info saved the day, buy me a beer!
