TEST 2: Verifying The MAP Sensor Is Getting Power
The manifold absolute pressure (MAP) sensor is fed power by the by the VIO/WHT wire of the MAP sensor connector.
The VIO/WHT wire connects to the MAP sensor connector terminal labeled with the number 2 in the photo above.
By the way, this power is in the form of 5 Volts DC and is supplied by your vehicle's Powertrain Control Module (PCM).
We'll use our multimeter to easily check to see if these 5 Volts are present (or not).
These are the steps:
With your multimeter still in Volts DC mode from the previous test and the key on (but engine off).
Probe the VIO/WHT wire that connects to the MAP sensor connector terminal labeled with the number 2, in the photo above, with the red multimeter test lead.
You can test for these 5 Volts with the MAP sensor's electrical connector connected to the MAP sensor or not, just avoid probing the front of the connector.
Now Ground the black multimeter test lead on the battery's negative post.
Your multimeter should register 4.5 to 5 Volts DC on its display.
OK, now that the testing part is done, let's take a look at what your results mean:
CASE 1: The VIO/WHT wire, of the MAP sensor connector, has 5 Volts DC: This is the correct result and it's starting to look like the MAP sensor is bad but you still need to check that the MAP sensor is getting Ground. For the Ground test, go to: TEST 3: Verifying The MAP Is Getting Ground.
CASE 2: The VIO/WHT wire, of the MAP sensor connector, DOES NOT have 5 Volts DC: This results lets you know that the MAP sensor is not bad, since without these 5 Volts DC, the MAP sensor can not function.
Although it's beyond the scope of this article to troubleshoot the cause of these missing 5 Volts, you have now eliminated the MAP sensor as bad. Resolving the issue that is keeping these 5 Volts from being supplied will solve the MAP sensor issue on your 2.5L V6 equipped Stratus (Cirrus, Avenger, or Sebring).
TEST 3: Verifying The MAP Sensor Is Getting Ground
Ground is fed to the manifold differential (MAP) sensor by the BLK/LT BLU wire of the MAP sensor's connector.
This BLK/LT BLU wire in turns connects directly to your vehicle's PCM (its the PCM that provides this Ground internally).
IMPORTANT: Be careful NOT to short the BLK/LT BLU wire, accidentally (or intentionally), to battery power or you will fry the PCM. Doing a voltage test with a multimeter, as described in the test steps below, is a safe way to test the BLK/LT BLU wire.
These are the steps:
With your multimeter still in Volts DC mode from the previous test and the Key On (but engine Off).
Probe the BLK/LT BLU wire with the black multimeter test lead.
It doesn't matter if you probe this circuit (wire) with the connector connected to the MAP sensor or not, but do not probe the front of the connector (if you decide to unplug the connector to test for this path to Ground).
Now connect the red multimeter test lead on the battery's positive (+) Post.
Your multimeter should register 10 to 12 Volts DC on its display.
OK, let's take a look at what your results mean:
CASE 1: The multimeter registered 12 Volts. This is the correct test result and it means that the manifold absolute pressure (MAP) sensor is being fed with ground by the PCM.
Taking into account all of your test results till this point, this also means that the MAP sensor on your 2.5L V6 equipped Stratus (Cirrus, Avenger, or Sebring) is fried and needs to be replaced.
Here's why: In MAP sensor TEST 1 and 2, you verified that the MAP sensor is not producing the correct values (when you applied vacuum) and that it does have power. Since in this test step you have confirmed that the MAP sensor does have a solid path to Ground, these results, interpreted together, indicate that the MAP sensor is bad.
CASE 2: The multimeter DID NOT register 12 Volts. Double check that you're testing the BLK/LT BLU wire and repeat the test... if your multimeter still does not show 10 to 12 Volts, then the manifold absolute pressure (MAP) sensor is not fried and NOT the cause of the MAP sensor diagnostic trouble code (DTC) issue.
Here's why: Without a good path to Ground, that the PCM provides internally, the MAP sensor will not work. With this test result, you have eliminated the MAP sensor as bad.
Although it's beyond the scope of this tutorial, you'll need to restore this missing Ground to get the MAP sensor issue (and trouble code) to go away.