P0108 MAP Sensor Code Explained (1996-2009 3.8L V6 Chrysler, Dodge, And Plymouth Minivan)

  • By: Abraham Torres-Arredondo
  • Created: 07 July 2025
  • Updated: 08 July 2025
  • Articl Id: 1108
P0108 MAP Sensor Code Explained (2002, 2003, 2004, 2005, 2006, 2007 3.8L V6 Chrysler, Dodge, And Plymouth Minivan)

If your 3.8L V6 Chrysler, Dodge, or Plymouth minivan is showing a P0108 MAP Sensor High Voltage code, this guide will help you understand what it means and how to fix it.

Code P0108 sets when the PCM sees a MAP signal that's too high for the engine's operating conditions —usually due to a faulty sensor, wiring issue, or power supply problem.

Since the MAP sensor plays a critical role in managing fuel injection and ignition timing, a bad reading can lead to poor performance, rough idle, or rich running.

In this tutorial, I'll walk you through what the code means, what causes it, and whether it makes sense to replace the sensor or test it first. I'll also link you to a complete step-by-step MAP sensor test you can do with a basic multimeter.

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: 1996.
  • 3.8L V6 Plymouth Grand Voyager: 1996, 1997, 1998, 1999.

MAP SENSOR MULTIMETER TESTS:

OTHER MAP SENSOR TROUBLE CODES EXPLAINED:

What Does P0108 Really Mean?

If your 1996–2009 3.8L V6 Chrysler, Dodge, or Plymouth minivan has set a P0108 code, here's what you'll likely see on the scan tool screen:

  • Generic OBD II Definition: P0108 – Manifold Absolute Pressure (MAP) Sensor Circuit High Input.
  • Chrysler Definition: P0108 – MAP Sensor Voltage Too High.

In simple terms, this means the PCM is seeing a voltage from the MAP sensor that's higher than it should be —usually over 4.5 Volts— for what the engine is actually doing.

Since this 3.8L V6 engine uses a speed-density system to manage fuel injection, the PCM relies heavily on the MAP sensor to estimate engine load and adjust fuel delivery in real time.

Normally, the MAP signal changes with vacuum: at idle, when manifold vacuum is high, the voltage is low (around 1.0 to 1.5 Volts). As engine load increases and vacuum drops, that voltage rises.

  • By "engine load", I mean stepping on the gas, driving uphill, hauling passengers, or running the A/C.

But when the PCM sees that MAP voltage stuck high —even when it shouldn't be— it flags a P0108 MAP Sensor High Voltage fault. That high reading throws off fuel calculations and messes with ignition timing.

Understanding what the PCM is reacting to gives you a head start on diagnosing the issue. Up next, we'll go over what kind of symptoms you can expect when this code pops up.

Common Symptoms Of A Code P0108

As mentioned in the previous section, when your 3.8L V6 Chrysler, Dodge, or Plymouth minivan sets a P0108 MAP Sensor High Voltage code, it means the PCM is reading a signal that suggests the engine is under heavy load —even if you're just idling or cruising.

This throws off the computer's ability to manage air/fuel ratios and ignition timing, which leads to all sorts of driveability issues. Here's what you might notice:

  • Strong fuel smell from the exhaust (running rich).
  • Hard starts or long crank time.
  • Rough idle, especially during cold starts.
  • Worse-than-usual gas mileage.
  • Sluggish throttle response or delayed acceleration.
  • Check engine light on (CEL).
  • Occasional stalling, especially at low speeds or when shifting to Drive.

These symptoms can be hit-or-miss —especially if the MAP sensor is acting up intermittently or there's a wiring issue affecting the signal. In the next section, I'll show you what usually causes a P0108 code on these minivans.

What Causes Code P0108?

Quite a few things can cause the MAP voltage signal to become stuck high. Here are the most common culprits:

  • Bad MAP sensor: Internal failure or short keeping voltage output too high.
  • Signal wire shorted to the 5V supply or to battery voltage somewhere in the engine wiring harness.
  • Connector issues or damaged wiring near the sensor —cracked or peeling insulation, or a damaged connector with loose terminals shorting against each other.
  • Oil fouling inside the sensor's vacuum port caused by blow-by gases entering the intake manifold.
  • PCM problem: Rare, but not impossible if everything else checks out.

So now the big decision: should you go ahead and replace the MAP sensor —or test it first and know for sure? That's what we'll cover next, so you can make the call with confidence.

Should You Replace The MAP Sensor?

When your 3.8L V6 Chrysler, Dodge, or Plymouth minivan sets a P0108 MAP sensor high voltage code, it's easy to jump straight to replacing the sensor.

And honestly? That's exactly what a lot of people do —including some repair shops. If the MAP sensor has shorted internally and is stuck putting out a high voltage, a replacement will fix it immediately.

If it doesn't? At least you've ruled out a common failure point and know it's time to look deeper. Since MAP sensors on these vans are usually easy to access and budget-friendly, it's often used as a first step in the troubleshooting process.

If that sounds like your plan, there's nothing wrong with it. Just make sure you're using a reliable replacement. Here are a couple of MAP sensors of known automotive brands I've used:

1996-2000:

2001-2003:

2004-2009:

Buying through these links helps keep this site going —and it doesn't cost you anything extra. Thanks for your support!

That said, I always suggest testing the sensor before swapping parts. You can check the sensor's voltage output, confirm it's getting 5 Volts and Ground, and make an informed decision —all with a basic multimeter.

Whether it turns out to be a faulty sensor or a wiring issue like a short-to-power on the signal wire, you'll know exactly what you're dealing with.

If you'd rather test it first, I've put together a complete how-to guide for the 3.8L V6 equipped minivans. You'll find it here:

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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