MAP Sensor Code Won't Go Away (1996-2009 3.8L V6 Chrysler, Dodge, And Plymouth Minivan)

  • By: Abraham Torres-Arredondo
  • Created: 07 July 2025
  • Updated: 07 July 2025
  • Articl Id: 1294
MAP Sensor Code Won't Go Away (1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 3.8L V6 Chrysler, Dodge, And Plymouth Minivan)

If you're still dealing with a P0107 or P0108 MAP sensor code on your 3.8L V6 Chrysler, Dodge, or Plymouth minivan —even after replacing the sensor— you're not alone.

This is a common headache on high-mileage vans, especially when the real issue isn't the sensor itself, but something wrong in its circuits between its connector and the PCM connector, such as:

  • Wiring damage.
  • Vacuum leaks.
  • Or even an intermittent PCM problem.

In this guide, I'll walk you through the real-world issues I've seen trigger persistent P0107 or P0108 codes, and how to test for them without guesswork.

Let's get to the bottom of it —and finally get that check engine light to stay off.

Contents of this tutorial:

APPLIES TO: This tutorial applies to the following vehicles:

  • 3.8L V6 Chrysler Town & Country: 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009.
  • 3.8L V6 Dodge Caravan: 1996, 1997, 1998, 1999, 2000, 2001.
  • 3.8L V6 Dodge Grand Caravan: 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009.
  • 3.8L V6 Plymouth Voyager: 1999.
  • 3.8L V6 Plymouth Grand Voyager: 1996, 1997, 1998, 1999.

MAP SENSOR MULTIMETER TESTS:

MAP SENSOR TROUBLE CODES EXPLAINED:

Was The MAP Sensor Really the Problem?

You've already replaced the MAP sensor —or maybe you followed the testing guide and confirmed it was working just fine. But that check engine light won't give up. The P0107 or P0108 code keeps coming back, and now you're wondering: what did I miss?

If that sounds familiar, you're not alone. I've been in that exact spot —double-checking everything, second-guessing my test results, and chasing a code that just wouldn't clear. Because here's the truth: sometimes the sensor isn't the issue —it's just reporting one.

Something else in the system is causing the MAP signal to look wrong, or the PCM is misinterpreting the data because of a problem somewhere else in the circuit.

Whether you're wrenching in your driveway with a multimeter or working in a shop with scan tools, the fact that you're digging deeper puts you ahead. In the next few sections, I'll walk you through the most common causes I've seen behind stubborn MAP sensor codes —and what you can do to fix them for good.

Connector And Wiring Issues That Cause False MAP Sensor Codes

Even if the MAP sensor itself is working just fine, a problem in the wiring or connector can fool the PCM into thinking it's not. This kind of issue is more common than people realize —especially on high-mileage minivans that have seen years of heat, oil vapor, moisture, or even rodent damage under the hood.

Here's what to watch for when inspecting the wiring and connector:

  • Corroded terminals inside the connector: Corrosion, even if it looks minor, can interfere with voltage and signal flow.
  • Wire break at the terminal: The wire may look fine on the outside, but the strands inside (the insulation) can snap right where the strands are crimped to the terminal. When this happens, only the insulation is holding it all together.
  • Cracked or peeling insulation: On these older minivans, the insulation near the connector can dry rot and fall apart (very common problem). This can lead to the wires shorting together and making contact and causing bad or erratic signals.
  • Signal wire shorted to power: A short between the MAP signal wire and the sensor's 5V supply wire can cause a falsely high reading —leading to a P0108 code.
  • Missing Ground or 5V reference signals: If either of these wires supplying Ground or 5 Volts is open, the sensor won't function, and the PCM may set a P0107 code instead.

Any of these issues can throw off the MAP signal and make the PCM think the sensor has failed. So before replacing more parts or giving up, take a good look at the wiring —especially right at the connector— and run some simple voltage and continuity tests with your multimeter.

It's also a smart idea to check the continuity of the MAP sensor's wires between the MAP connector and the PCM connector. With the PCM unplugged, you can verify that none of the three wires are shorted together or to other circuits. These checks can catch hidden problems buried in the engine wiring harness.

If you find any connector or wiring issues, fix those first. Even a small wiring fault can mimic a bad sensor and keep that MAP code coming back, lighting up your dash every time you start the van.

Don't Rule Out A Bad New Sensor

Here's a hard-earned truth from years in the field: sometimes, new parts are bad right out of the box.

I've opened factory-sealed sensors (and especially ignition system components), installed them with confidence —only to find out they didn't work at all. Most didn't work from the get-go, others it took a few days for the part to fail.

These sensors are mass-produced in large batches and shipped worldwide. Every once in a while, a defective one slips through quality control —and unfortunately, it might be the exact one you picked up.

If you've already replaced the MAP sensor and the P0107 or P0108 code still won't clear, there's a real chance the replacement part is no good.

The fix? Test the sensor you just installed. A simple vacuum test with a multimeter will tell you everything you need to know —and could save you from more wasted time (and money).

If you haven't tested it yet, check out the exact guide you need below. Just pick the version that matches your year:

Vacuum Integrity: Cracks, Leaks, and Oil Contamination

The MAP sensor pulls its vacuum reading directly from the intake manifold —so anything that interferes with that vacuum can send bad data to the PCM and trigger false MAP sensor trouble codes.

These kinds of issues are pretty common on high-mileage 3.8L minivans, and the tricky part? You won't see them on a multimeter.

If you're still trying to track down a stubborn MAP sensor code, take a few minutes to check for these often-overlooked problems:

  • Cracked or missing O-Ring(s) at the MAP sensor: The sensor seals to the intake manifold with an O-Ring. Over time, that O-Ring can dry out, shrink, or crack —letting air sneak past and throwing off the vacuum reading. If it looks brittle or worn, swap it out.
  • Leaking intake manifold gaskets: The lower intake manifold "valley pan" gasket is infamous for causing vacuum leaks. That unmetered air can skew the MAP reading and trigger false codes. You can test for this using carb cleaner —here's how:
  • Oil fouling inside the MAP sensor: On engines with heavy blow-by, oil vapor can work its way into the intake manifold —and from there, into the MAP sensor. A little oil in the vacuum port can throw off pressure readings even if the electrical side of the sensor is still fine. Pull the sensor out and check for signs of oil inside the port.
  • Loose intake bolts or warped manifold surfaces: On the 2000+ models, the plastic upper intake manifolds don't use high torque like older aluminum designs. Over time, bolts can loosen or the sealing surface can warp slightly, letting in unmetered air. A quick torque check and visual inspection could save you hours of head-scratching.

Weak Fuel Pump Can Cause Lean Conditions

If the fuel pump in your 3.8L V8 Chrysler, Dodge, or Plymouth minivan is starting to fail (as in it hasn't completely died) and can't keep up with demand, the engine may start running lean —especially under load.

While this more commonly triggers lean codes like P0171 or P0174, a lean condition can also throw off manifold vacuum and confuse the PCM into setting a MAP sensor code.

Here's why: when the engine runs lean due to low fuel volume or pressure, combustion becomes unstable —particularly during acceleration or climbing hills. That weak burn affects the engine's ability to maintain normal vacuum levels, and the MAP sensor ends up reporting numbers the PCM doesn't expect. The PCM sees that as a fault and may blame the sensor.

If you've ruled out wiring, the sensor, and vacuum leaks, but your MAP code still won't go away, it's worth checking your fuel pressure with a gauge. A weak pump can hide in the background until the system is pushed —and that's usually when things start going sideways.

Engine Conditions That Confuse The PCM

Even if your MAP sensor and wiring and the fuel pump are working just fine, there are mechanical engine issues that can trick the PCM into thinking something's wrong with the sensor —especially on speed-density systems like the one used in your 3.8L V8 Chrysler, Dodge, or Plymouth minivan.

Here are some real-world examples I've seen that can throw off the MAP signal even when the sensor is fine:

  • Low cylinder compression: Weak compression in one or more cylinders can lower overall intake manifold vacuum. The PCM sees that lower vacuum and interprets it as a problem with the MAP sensor.
  • Late valve timing: A stretched timing chain or incorrect timing chain installation after engine work can throw off cam-to-crank alignment. That messes with intake vacuum and confuses the PCM's engine load calculations based on MAP data.
  • Exhaust restriction: A clogged catalytic converter or damaged exhaust pipe can cause excessive backpressure, affecting airflow and altering vacuum readings. The PCM may see this as a MAP sensor issue when it's really a restriction downstream.

These types of engine problems can imitate a bad MAP sensor and even trip up the PCM. So if everything else checks out —wiring, sensor, vacuum integrity— it may be time to test compression or inspect your timing components, especially if your minivan has high mileage or recent engine work.

What If The PCM Is The Problem?

It's not common, but it does happen —the PCM itself can be the source of a MAP sensor issue. It's one of those problems that shows up after you've already ruled everything else out, and it's always the last thing anyone wants to suspect.

What usually happens is a failure inside the PCM's circuitry —specifically the part that supplies the 5 Volt reference or reads the MAP sensor signal. When that part fails, the PCM might log a P0107 or P0108 code even though the wiring and sensor are fine.

The silver lining is that a bad PCM often doesn't fail quietly. You'll typically see weird behavior across other systems too —like multiple sensors throwing codes or acting up, especially if they share the same 5 Volt or Ground circuits.

Before pointing the finger at the PCM, make sure you've ruled out these basics:

  • MAP sensor tested or replaced: Confirm it's working or already swapped out.
  • All three wires have solid continuity: From the MAP connector to the PCM connector.
  • No shorts between the sensor wires: Check for wire-to-wire contact (continuity) that shouldn't be happening.
  • Sensor connector in good shape: The connector shell and the terminals are in good shape.
  • No other sensors dragging down the circuit: Especially ones that share the MAP sensor's 5 Volt or Ground source.
  • PCM Ground circuits checked: Don't skip this —voltage drop testing the Grounds is a must.

If everything above checks out and that MAP code just won't go away, then yeah and although very rare —the PCM might be the culprit.

At that point, I recommend getting a second opinion from a professional tech. If you bring your test results with you, it'll help them give you a much clearer and more accurate next step.

More 3.8L V6 Chrysler, Dodge, And Plymouth Minivan Diagnostic Tutorials

Need help figuring out what's going on with your 3.8L V6 equipped minivan? This index brings together all my step-by-step tutorials in one place, so you can get to the root of the problem faster.

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