In this tutorial, I'll show you how to accurately test the manifold absolute pressure (MAP) sensor on your 4.7L Dodge Durango (Dakota) using a simple multimeter.
At the end of the tutorial, I'll also show you where you can buy it and save a few bucks.
Tutorial contents at a quick glance:
- Symptoms of a BAD MAP Sensor.
- TEST 1: Checking the MAP Sensor Signal.
- TEST 2: Verifying the MAP Sensor is Getting Power.
- TEST 3: Verifying the MAP Sensor is Getting Ground.
- MAP Sensor Code Won't Go Away.
- Where to Buy the MAP Sensor and Save.
- More 4.7L Dodge Tutorials.
If you're needing the MAP sensor test for 2000-2001 4.7L Durango, 4.7L Dakota, check out the following tutorial: How to Test the MAP Sensor (2000-2001 4.7L Dakota, Durango).
You can find this tutorial in Spanish here: Cómo Probar el Sensor MAP (2002-2009 4.7L Dakota, Durango) (at: autotecnico-online.com).
Symptoms of a BAD MAP Sensor
The fuel system on your 4.7L Dodge Durango (Dakota) relies heavily on the manifold absolute pressure (MAP) sensor to help calculate the amount of air entering the engine.
So, when the MAP sensor fails... it causes quite a bit of havoc on engine performance. The most obvious symptom, of a failed MAP sensor, is the check engine light (CEL) will be shining nice and bright (and a MAP sensor trouble code stored in the PCM's memory).
Here's a list of the symptoms you'll see with a failed MAP sensor:
- Diagnostic trouble codes (DTCs):
- P0106: Manifold Absolute Pressure Sensor Performance.
- P0107: Manifold Absolute Pressure Sensor (MAP) Circuit Low.
- P0108: Manifold Absolute Pressure Sensor (MAP) Circuit High.
- Doesn't pass the smog check.
- Engine idles rough.
- Engine takes forever to start (extended cranking time).
- Engine doesn't start.
- Black smoke coming out of the tail-pipe as engine runs.
Let's jump into the first test in the next subheading...
TEST 1: Checking the MAP Sensor Signal
Testing the MAP sensor involves tapping into its signal wire with a multimeter and checking to see if it produces a correct voltage signal.
This voltage signal reacts (increases/decreases) to the amount of vacuum the MAP sensor senses on its vacuum port.
To accurately test the MAP sensor... we need to bypass the engine and manually apply vacuum to the MAP sensor ourselves.
This is due to the fact that quite a few things (problems) can cause the engine's vacuum to fool the PCM into thinking the MAP sensor is bad when it isn't.
Don't worry, this is pretty easy test. You can apply vacuum to the MAP sensor using a vacuum pump or, if you don't have a vacuum pump... you can use your mouth.
NOTE: The ignition key must be in the On position and MAP sensor must remain connected to its connector during this test.
OK, to get this show on the road, this is what you need to do:
Remove the MAP sensor from its place on the intake manifold.
Connect your vacuum pump to the MAP sensor's vacuum port using a vacuum hose. Before you proceed to the next step, make sure the MAP sensor is connected to its connector.
With your multimeter in Volts DC mode probe the VIO/BRN wire of the MAP sensor connector. The VIO/BRN wire is the one that connects to MAP sensor pin #1 in the illustration above.
You'll need to use a tool like a wire piercing probe to access the signal inside the wire. To see what a wire piercing probe looks like, go here: Wire Piercing Probe.
Ground the BLACK multimeter test lead directly on the battery negative terminal.
Turn the Key on but don't start the engine. At this point your multimeter should register about 3.8 to 4.0 Volts DC.
Now, pump the vacuum pump to apply vacuum to the MAP sensor. The voltage should drop down to 1.1 Volts.
Repeat this test step several times and each time, you should see the same values on your multimeter.
OK, let's take a look at what your vacuum pump test results mean:
CASE 1: Your multimeter registered the indicated voltages as you applied vacuum: This tells you that the manifold absolute pressure sensor is OK (not defective).
Now, if your vehicle still has the MAP sensor code lighting up the check engine on your instrument cluster.. take a look at the section: MAP Code Won't Go Away for more info.
CASE 2: Your multimeter registered voltage, but it did not increase or decrease as you applied vacuum: This confirms that the manifold absolute pressure (MAP) sensor on your 4.7L Dodge is BAD. Replacing the MAP sensor will solve the MAP sensor trouble code lighting up the check engine light.
CASE 3: Your multimeter registered 0 Volts: This usually means that the MAP sensor is fried. To be absolutely sure, I suggest confirming that the MAP sensor has power and ground. If both (power and ground) are present, the MAP sensor is BAD. To test for power, go to TEST 2: Verifying the Manifold Absolute Pressure Sensor is Getting Power.