DTC P0108 – How To Service Your Honda Civic MAP Sensor

The Manifold Absolute Pressure Sensor is responsible for providing the real time engine vacuum and pressure values to your Honda Civic’s ECU. With this signal the ECU is able to then operate the motor efficiently, by way of fuel and ignition controls. When your Manifold Absolute Pressure ( MAP ) sensor is having problems or has gone bad, you can get this OBDII DTC P0108 Trouble Code.

Today we’ll be showing you how to test, service and replace the MAP sensor in a 1997 Honda Civic EX. This walkthrough will show you the step by step breakdown on what to do when your MAP sensor needs service.

What is the DTC P0108

The MAP sensor is usually a three or five wire sensor that relays a 0-5 volt reference that is supposed to signify engine pressure. The more pressure in your intake manifold, the more voltage your ECU will see and more fuel will be delivered accordingly.

When your Honda Civic ECU sees a value greater than 5 volts, it will trigger the DTC P0108 trouble code. Symptoms that arise from this OBDII code can range from annoying symptoms like sluggish driving, bad throttle response, and bad fuel economy.

Where is my MAP SENSOR located?

Your MAP sensor is located on your throttle body assembly, which is under your intake tract and airbox. Let’s get started on our how to service your Honda Civic MAP Sensor guide, with a look at our engine the VTEC D16Y8.

To access your MAP sensor, most of your intake tract and air box must be removed in order to access the sensor and the 3 pin weatherproof connector.

Tools you will need to complete this job :  

• flathead screwdriver
• 8mm socket
• 10mm socket
• Multimeter

First unplug your air intake temperature sensor and double check the connector for any loose debris or dirt.

With your AIT unplugged now you can move onto the stock Civic airbox. Undo the metal band clips that hold the top of your airbox onto the base. Once all the metal clips are off, pull off the top half of your stock air box and push the entire intake snorkel to the side.

With the top half of your airbox off, you should see your factory airfilter element. Remove this element to expose the throttle body and the lower part of the intake box.

If you have an upgradable filter element, such as K&N now would be a good time to get that ready for install.

Now disconnect the vacuum tube shown here by depressing the metal clips and pulling them down to the metal tubing. Pull off this hose from your lower air box to gain access to the MAP sensor, which is directly below it.

Remove the 8mm bolt that secures the lower air box in place. Once you have this 8mm bolt removed you can undo the metal clamp that holds the lower air box to your throttle body.

Once the 8mm clamp that holds the throttle body inlet in place is loosened, pull up on the air box base to remove the airbox all together.

You should now be able to see your Honda Civic MAP Sensor, and the three pin weatherproof connector is circled above. The Honda Civic OBDII MAP pinout is shown below.

Now using your multimeter is similar device, read the switched power wire, or wire 1 on your MAP sensor for switched power to the sensor. Make sure the ignition key is set to the “ON” position, so that your MAP sensor is powered.

Next check the middle wire which is green with a white stripe for the low reference circuit or the ground. And lastly will be the signal wire, which is a black with red stripe. This wire transmits the real time vacuum values to your ECU, and you should see a range here of 0-1 volts at idle.

You can also unbolt your Honda Civic MAP sensor with the harness still attached, and use a air compressor to blow pressure into the sensor while measuring the signal wire.

Test your Honda Civic MAP sensor signal wire

To properly test your Honda Civic MAP sensor, you will need to unbolt it from your throttle body. To do this however you need a short phillips and maybe a lot of elbow grease because your MAP sensor is very close to your Honda Civic firewall.

Because space is so limited, you may be forced to remove the entire throttle body assembly from your Honda Civic. Here’s a look at the two screws that must be removed in order for you to remove the Honda Civic MAP sensor.

Now that you have your Honda Civic MAP sensor removed, you can reconnect the MAp sensor wiring connector. Turn the key to the “ON” position and insert your multimeter’s positive lead into the 3rd ( black with red stripe ) wire to test voltage. Ground your negative multimeter lead if applicable and measure the voltage at the signal wire.

You should see around 1.0 volts with the MAP sensor exposed to atmospheric pressure. Try blowing into the MAP sensor or use a air compressor with air nozzle to gently blow pressure into the MAP sensor. You should see a clear and smooth range of voltage that rises with the amount of pressure you are providing.

If your MAP sensor is “jumping” voltage, or doesn’t read the full 5 volts no matter how much pressure you are blowing through it, it’s bad. Replace your 1997 Honda Civic MAP sensor, part numbers are below :

HONDA OE 37830-P0GS00
HONDA OE 37830-PAA500
HONDA OE 37830-PAAS00
HONDA OE 37830-POGS00

That does it for our How To Service Your Honda Civic MAP Sensor Guide, please leave us any questions or comments you may have below!