Testing the MAP sensor can easily be done with a multimeter (no scan tool required) and in this tutorial, I'll show you how.
With your test results, you'll quickly find out if the MAP sensor is working correctly or if it has failed and causing an engine performance problem.
Contents of this tutorial:
- Symptoms Of A Bad MAP Sensor.
- Where To Buy The MAP Sensor And Save.
- MAP Sensor Circuit Descriptions.
- TEST 1: Testing The MAP Sensor Signal Key On Engine Off.
- TEST 2: Applying/Releasing Vacuum To The MAP Sensor.
- TEST 3: Making Sure The MAP Sensor Is Getting 5 Volts.
- TEST 4: Making Sure The MAP Sensor Is Getting Ground.
- MAP Sensor Code Won't Go Away.
- More 2.4L Honda Accord Test Tutorials.
APPLIES TO: This tutorial applies to the following vehicles:
- 2.4L Honda Accord: 2003, 2004, 2005, 2006, 2007 2.4L Honda Accord.
Symptoms Of A Bad MAP Sensor
The manifold absolute pressure (MAP) sensor plays a critical role in the fuel injection system of your 2.4L Honda Accord.
When the MAP sensor fails, you're going to see one or more of the following engine performance issues:
- Check Engine Light: The check engine light will be shining nice and bright on your dashboard and one of the following diagnostic trouble codes will stored in the computer's memory:
- P0106: MAP Sensor System Performance.
- P0107: MAP Sensor Circuit Low Voltage.
- P0108: MAP Sensor Circuit High Voltage.
- Engine Hard Start: A bad MAP sensor can make the engine take a long time to start.
- Poor Engine Performance: You may experience a lack of power or hesitation during acceleration, especially under heavy loads or at higher speeds.
- Rough Idling or Stalling: The engine may idle rough or even stall unexpectedly.
- Decreased Fuel Efficiency: A faulty MAP sensor can disrupt the air-fuel mixture, causing the engine to run either too rich (excessive fuel) or too lean (insufficient fuel). The end result is bad gas mileage.
- Black Smoke from Exhaust: An overly rich air-fuel mixture due to a faulty MAP sensor can result in black smoke coming out of the exhaust pipe.
- Stalling at Idle: The engine may stall when idling.
- Hesitation or Surging: You might notice hesitation or surging during acceleration or while driving at a consistent speed.
- Engine No-Start: The engine cranks, but doesn't start.
Where To Buy The MAP Sensor And Save
The following links will help you comparison shop for the manifold absolute pressure (MAP) sensor. The recommended MAP sensors are of known automotive brands -no knockoff MAP sensors!
Not sure if the MAP sensor fits your vehicle? Don't worry. Once you get to the site, they'll make sure it fits by asking you the specifics of your vehicle. If it doesn't fit, they'll find you the right MAP sensor.
MAP Sensor Circuit Descriptions
| Wire | Color | Description |
|---|---|---|
| 1 | Yellow with red stripe (YEL/RED) | 5 Volts (from PCM) |
| 2 | Green with red stripe (GRN/RED) | MAP signal |
| 3 | Green with white stripe (GRN/WHT) | Ground (from PCM) |
TEST 1: Testing The MAP Sensor Signal Key On Engine Off
To get our MAP sensor diagnostic started, we're going to check its signal output with the key on and engine off.
What we're looking for, is for the MAP sensor voltage signal to be somewhere between 4 to 4.5 Volts with the key on and engine off.
To accomplish this test, we'll connect our multimeter to the green with red stripe (GRN/RED) wire of the MAP sensor's 3-wire connector.
In the photo above, I've labeled the GRN/RED wire with the number 2 so that you can easily identify it on your Honda Accord.
IMPORTANT: The MAP sensor must remain connected to its electrical connector to read the voltage within its signal wire. You'll need to use a back probe on the connector or a wire piercing probe on wire. You can see an example of this tool here: Wire Piercing Probe.
OK, these are the test steps:
- 1
Connect the black multimeter test lead directly on the battery negative (-) terminal.
- 2
Place your multimeter in Volts DC mode.
- 3
Connect the red multimeter probe to the GRN/RED wire of the MAP sensor's 3-wire connector.
In the photo above, I've labeled the GRN/RED wire the number 2.
IMPORTANT: The MAP sensor must remain connected to its 3-wire connector. - 4
Turn the key ON but don't start the engine.
- 5
At this point your multimeter should register a value of around 4 to 4.5 Volts DC.
OK, let's examine your test results:
CASE 1: Your multimeter registered the indicated voltage. This is the correct result.
Your next step is to test the MAP sensor's voltage signal when applying/releasing vacuum to the sensor. Go to: TEST 2: Applying/Releasing Vacuum To The MAP Sensor.
CASE 3: Your multimeter DID NOT register the indicated voltage. This test result generally tells you that the MAP sensor is bad, not getting power, or Ground.
Before replacing the MAP sensor, we need to perform three more tests. For the first of these two, go to: TEST 2: Applying/Releasing Vacuum To The MAP Sensor.