Testing the MAP sensor, on the 3.8L V6 Grand Caravan (Town & Country, Grand Voyager), is not difficult since it's very easy to access it.
In this tutorial, I'll explain the 3 easy tests you need to perform to find out if it's bad or not.
Also, you don't need a scan tool to test the MAP sensor. I'll show you how to test it using a multimeter.
If your check engine light is illuminated by a P0108 or a P0109 diagnostic trouble code, this is the tutorial you need.
Contents of this tutorial:
- Symptoms Of A Bad MAP Sensor.
- How The MAP Sensor Works.
- Should I Just Replace The MAP Sensor?
- Where To Buy The MAP Sensor And Save.
- TEST 1: Checking The MAP Signal With A Multimeter.
- TEST 2: Making Sure The MAP Sensor Is Getting 5 Volts.
- TEST 3: Making Sure The MAP Sensor Is Getting Ground.
- More 3.8L V6 Chrysler, Dodge, And Plymouth Minivan Diagnostic Tutorials.
You can find this tutorial in Spanish here: Cómo Probar El Sensor MAP (1996-2000 3.8L V6 Chrysler, Dodge, Plymouth Minivan) (at: autotecnico-online.com).
APPLIES TO: This MAP sensor test tutorial applies to the following vehicles:
- 3.8L V6 Chrysler Town & Country: 1996, 1997, 1998, 1999, 2000.
- 3.8L V6 Dodge Grand Caravan: 1996, 1997, 1998, 1999, 2000.
- 3.8L V6 Plymouth Grand Voyager: 1996, 1997, 1998, 1999, 2000.
HOW THE MAP SENSOR WORKS:
RELATED MAP SENSOR TESTS:
- How To Test The MAP Sensor (1994-1995 3.8L V6 Chrysler, Dodge, And Plymouth Minivan).
- How To Test The MAP Sensor (2001-2004 3.8L V6 Chrysler And Dodge Minivan).
- How To Test The MAP Sensor (2004-2007 3.8L V6 Chrysler And Dodge Minivan).
Symptoms Of A Bad MAP Sensor
The 3.8L V6 engine, covered by this tutorial, uses a 'speed density' fuel injection system.
What this means in plain English, is that the fuel injection computer needs to know 3 things to calculate the amount of air entering the engine and to calculate the amount of fuel to inject into the engine.
Those three things are: intake air temperature, engine RPM, and engine load.
The MAP sensor is the one tasked with informing the computer the engine load. It does this by measuring the amount of intake manifold pressure.
Since the MAP sensor is a critical component of the fuel injection system, when it fails the engine is going to suffer one or more of the following symptoms:
- MAP sensor diagnostic trouble code (DTC) stored in the vehicle's computer's memory:
- P0107: MAP Sensor Voltage Too Low.
- P0108: MAP Sensor Voltage Too High.
- Bad gas mileage.
- Black smoke coming out of the tail pipe, especially when you accelerate the vehicle.
- No power and/or hesitation as you accelerate the vehicle. It feels like all of a sudden someone cut the power out momentarily as you step on the gas to get the vehicle moving.
If the PCM has set either a P0107 or a P0108 and want a better understanding of what they really mean, check out these step-by-step breakdowns:
- P0107 MAP Sensor Code Explained (1996–2009 3.8L V6 Chrysler, Dodge, And Plymouth Minivan).
- P0108 MAP Sensor Code Explained (1996–2009 3.8L V6 Chrysler, Dodge, And Plymouth Minivan).
How The MAP Sensor Works
The manifold absolute pressure (MAP) sensor's job is to measure the amount of vacuum that is created by the downward stroke of the engine pistons and is one of the most important inputs the PCM needs to make your minivan run optimally.
So here, in a nutshell, is how the MAP sensor works when you crank and start your 3.8L V6 Chrysler (Dodge, Plymouth) minivan:
- The fuel injection computer (PCM) supplies 5 Volts and Ground to power the MAP sensor.
- At idle, the MAP sensor sends the PCM a low voltage signal —typically around 1.1 to 1.8 Volts— because intake manifold vacuum is high.
- When you step on the accelerator, the throttle plate opens, vacuum drops, and the MAP sensor responds by increasing its signal voltage —often rising to 4.0 Volts or more.
- With this rising voltage, the PCM knows the engine is under load and adjusts fuel injection, ignition timing, and other systems to keep things running smoothly.
- When you let off the gas and the throttle closes, vacuum increases again, the MAP voltage drops, and the PCM goes back to managing idle conditions —until the next time you hit the gas.
For a more in-depth look at what the MAP sensor does, take a look at this guide:
Pretty easy stuff? The cool thing is that testing the MAP sensor's performance is as easy too.
Should I Just Replace The MAP Sensor?
Let's be real —when you see a P0107 or P0108 code pop up on your 1996–2000 3.8L V6 equipped minivan, it's completely normal to want to cut to the chase and replace the MAP sensor.
And in many cases, that gets the job done —heck, even shops usually approach this issue the same way. No shame in that at all.
The sensor is easy to reach, doesn't break the bank, and takes less time to swap out than it does to run to the coffee shop and grab a cup. So if you're short on time, don't have the tools, or just want to try the quickest fix first —I totally get it.
If you're leaning that way, here are two MAP sensors from trusted automotive brands I personally recommend —ones I've used many times with solid results:
- Walker Products 225-1011 MAP Sensor (Amazon affiliate link)
- Premier Gear PG-MAP1010 MAP Sensor (Amazon affiliate link)
These links help support this site and the free info I put out —and they won't cost you a dime extra. If you choose to use them, thank you sincerely!
That said, if you're the kind of person who likes to confirm a part's actually bad before replacing it —this guide will walk you through it step by step. All it takes is a simple multimeter, a vacuum pump, and a few minutes of your time.
Ready to dig in? Here's where to start: TEST 1: Checking The MAP Signal With A Multimeter.
Where To Buy The MAP Sensor And Save
If it’s time to swap out the MAP sensor, here are two solid options I recommend —from brands I've personally used and had good results with on both customer jobs and my own vehicles:
Disclosure: As an Amazon Associate, I earn from qualifying purchases. Buying through these links helps support this site at no extra cost to you. I truly appreciate it!
NOTE: If you're not sure if the above MAP sensor fit your particular 3.8L V6 Chrysler (Dodge, Plymouth) minivan 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.
TEST 1: Checking The MAP Signal With A Multimeter
The very first thing that we're going to do is remove the MAP sensor from the intake manifold and then connect a multimeter to the MAP signal voltage wire.
Then we're going to manually apply vacuum to the sensor.
The purpose of this test, is to see if the MAP signal voltage reacts to the vacuum that we're going to apply and release to the MAP sensor.
Generally, when the MAP sensor fails, the MAP signal voltage will stay stuck in one value no matter how much vacuum is applied to the sensor.
The correct and expected test result is for the MAP signal voltage to decrease as vacuum is applied to it and for the voltage to increase (back to the original value) as vacuum is released.
This is a pretty easy test and on which should take you about 15 minutes or less to do. If you don't own a vacuum pump, don't worry. You can apply vacuum to the MAP sensor with your mouth or you can rent one from your local AutoZone (or O'Reilly Auto Parts).
You'll need a multimeter to test your vehicle's MAP sensor. If you don't have one and need to buy one or upgrade yours, the following recommendation will help:
- Tekpower TP8268 AC/DC Auto/Manual Range Digital Multimeter (Amazon affiliate link).
IMPORTANT: The MAP sensor must remain connected to its electrical connector to read its voltage signal. You'll need to use a back-probe on the connector or a wire-piercing probe on the wire to access the MAP signal. You can see an example of this tool here: Wire Piercing Probe Review.
OK, let's start:
- 1
Remove the MAP sensor from the intake manifold.
If you needed to disconnect the MAP sensor from it's electrical connector to remove it, reconnect it now (the MAP sensor must remain connected to its connector for this test). - 2
Select Volts DC Mode on your multimeter.
- 3
Connect the red multimeter test lead to the dark green with red stripe (DK GRN/RED) wire of the MAP sensor's connector.
NOTE: The MAP sensor must remain connected to its electrical connector to test the MAP signal voltage. - 4
Ground the black multimeter test lead on the battery negative (-) terminal.
- 5
Have your helper turn the key On but don't start the engine.
- 6
You should see a voltage around 4.5 Volts DC registering on your multimeter. If it doesn't, don't worry about it just yet, continue with the other steps.
- 7
Connect your vacuum pump to the MAP sensor using a large diameter hose (I use a 3/8 fuel hose).
Whatever hose you use, it's important that it makes a tight seal on both the MAP sensor's vacuum inlet nipple and the vacuum hose. - 8
Apply vacuum to the MAP sensor till the gauge's needle reaches 5 in. Hg of vacuum. These are the readings you should have as you pump the vacuum pump to different vacuum levels:
1.) 0 in. Hg ...... 4.7 Volts.
2.) 5 in. Hg ...... 3.9 Volts.
3.) 10 in. Hg .... 3.0 Volts.
4.) 15 in. Hg .... 1.1 Volts. - 9
Release the vacuum you've applied. The voltage reading should go back up to the value you registered in step 6.
Let's take a look at what your test results mean:
CASE 1: As you applied/released vacuum, the voltage decreased/increased. This is the correct test result.
You can conclude that the manifold absolute pressure (MAP) sensor is working fine and is not defective. No further MAP sensor tests are needed.
If you've run all the tests and that MAP sensor code still won't clear, take a look at this companion article that'll walk you through often-overlooked causes that can keep triggering a MAP code, even after replacing the sensor:
CASE 2: As you applied/released vacuum, the voltage DID NOT decrease/increase. This test result usually confirms that the MAP sensor is fried and that it needs to be replaced. But before you replace it, make sure it's getting 5 Volts and Ground.
The next test is to make sure that the MAP sensor is getting 5 Volts. Go to: TEST 2: Making Sure The MAP Sensor Is Getting 5 Volts.
CASE 3: The multimeter DID NOT register any voltage. This isn't good, but doesn't condemn the manifold absolute pressure (MAP) sensor as bad yet.
The next test is to make sure that the MAP sensor is getting 5 Volts. Go to: TEST 2: Making Sure The MAP Sensor Is Getting 5 Volts.
TEST 2: Making Sure The MAP Sensor Is Getting 5 Volts
The MAP sensor needs 5 Volts DC to create its vacuum voltage signal.
In this test section, we're going to make sure that the MAP sensor is getting them.
The wire that provides these 5 Volts DC, to the MAP sensor, is the violet with white stripe (VIO/WHT) wire of the sensor's 3-wire connector.
In the photo above, the female terminal labeled with the number 2 is the one that connects to the VIO/WHT wire.
We'll do a simple multimeter voltage test to find out if these 5 Volts are present in the violet with white stripe wire.
If 5 Volts are present in the wire, the next step is to make sure that the MAP sensor is getting Ground on the black with light blue stripe wire.
These are the test steps:
- 1
Place your multimeter in Volts DC mode.
- 2
Disconnect the MAP sensor from its electrical connector.
- 3
Gently probe the terminal labeled number 2 in the photo above with the red multimeter test lead.
NOTE: Be careful and don't damage the female terminal. - 4
Connect the black multimeter test lead to the negative (-) battery terminal.
- 5
Have a helper turn the key on but don't start the engine.
- 6
The multimeter should display 4.5 to 5 Volts on its screen.
Let's examine your test result:
CASE 1: The multimeter registered 4.5 to 5 Volts. This is the correct test result and confirms that the fuel injection computer and the circuit (wire) is supplying the MAP sensor with power.
The next step is to make sure that the manifold absolute pressure (MAP) sensor is getting Ground. For this test go to: TEST 3: Making Sure The MAP Sensor Is Getting Ground.
CASE 2: The multimeter DID NOT register 4.5 to 5 Volts. Without these 5 Volts the manifold absolute pressure sensor will not function.
The two most likely reasons for this are: 1) an open-circuit problem in the wire or 2) the fuel injection computer may be fried.
Altho' it's beyond the scope of this tutorial to test these two conditions, you have now eliminated the manifold absolute pressure (MAP) sensor on your 3.8L V6 Chrysler (Dodge, Plymouth) minivan as being the cause of the problem and/or the MAP sensor diagnostic trouble code (DTC) lighting up the check engine light (CEL).
TEST 3: Making Sure The MAP Sensor Is Getting Ground
If you've reached this point, you have confirmed that:
- The MAP signal voltage does not decrease/increase as you apply/release vacuum to the sensor.
- The MAP sensor is getting 5 Volts from the VIO/WHT wire.
In this last test section, we're going to make sure that the MAP sensor is getting Ground.
The wire that provides Ground to the MAP sensor, is the the black with light blue stripe (BLK/LT BLU) wire of the sensor's 3-wire connector
In the photo above, the black with light blue stripe wire connects to the female terminal labeled with the number 1.
IMPORTANT: If you probe the front of the female terminal, probe it very gently with your multimeter test leads. Or you run the risk of damaging the terminal.
CAUTION: The fuel injection computer provides Ground for the MAP sensor. Be careful and don't short the wire to battery 12 Volts or you'll fry the computer. The multimeter voltage test I'm suggesting is a safe way to test for Ground in this wire.
Let's get testing:
- 1
Place your multimeter in Volts DC mode.
- 2
Disconnect the MAP sensor from its electrical connector.
- 3
Gently probe the terminal labeled number 1 in the photo above with the black multimeter test lead.
NOTE: Be careful and don't damage the female terminal. - 4
Connect the red multimeter test lead to the battery positive (+) terminal.
- 5
Have your helper turn the key on but don't start the engine.
- 6
Your multimeter should display 10 to 12 Volts if Ground is present.
Let's examine your test result:
CASE 1: The multimeter showed 10 to 12 Volts. This is the correct test result and tells you that the fuel injection computer and the wire/circuit (that supply this Ground) are OK.
This multimeter test result also confirms that the MAP sensor is bad and needs to be replaced if you have confirmed:
- That the MAP voltage signal does not decrease when you apply vacuum to the MAP sensor (TEST 1).
- That the VIO/WHT wire is supplying 5 Volts DC (TEST 2).
- That the BLK/LT BLU wire is supplying Ground.
Here are two MAP sensors I personally recommend —from brands I've used in the field and had solid results with over the years:
- Walker Products 225-1011 MAP Sensor (Amazon affiliate link)
- Premier Gear PG-MAP1010 MAP Sensor (Amazon affiliate link)
Buying through these links helps support this site and keeps these free tutorials coming —at no extra cost to you. It's a small way to say thanks, and I truly appreciate it.
CASE 2: The multimeter DID NOT show 10 to 12 Volts. This test result indicates a problem with either the PCM (internal fault/problem) or an open in the wire between the MAP sensor and the PCM itself.
Altho' testing these two conditions are beyond the scope of this tutorial, you have now eliminated the MAP sensor on your 3.8L V6 Chrysler (Dodge Plymouth) minivan as being the cause of the problem and/or the MAP sensor diagnostic trouble code (DTC) lighting up the check engine light (CEL).
More 3.8L V6 Chrysler, Dodge, And Plymouth Minivan Diagnostic Tutorials
If you're tackling a check engine light or an engine performance problem on your 3.8L V6 equipped minivan, this index can really help. It's packed with practical tutorials written for DIYers and Pros alike.
Here's a sample of the tutorials you'll find in the index:
- How To Check For Vacuum Leaks: Carb Cleaner Spray (1994-2009 3.8L V6 Chrysler, Dodge, And Plymouth Minivan).
- Common Causes Of Spark Plug Failure (1994-2010 3.8L V6 Chrysler, Dodge, And Plymouth Minivan).
- How To Test A Blown Head Gasket (1994-2010 3.8L V6 Chrysler, Dodge, And Plymouth Minivan).
- How To Test Engine Compression (1994-2010 3.8L V6 Chrysler, Dodge, And Plymouth Minivan).
If this info saved the day, buy me a beer!
