Nissan Pathfinder P0105 Trouble Code – Test your Pressure Sensor
When you see your Nissan Pathfinder check engine light on, the first thing you must do is to read the code. This can be done using a OBDII scan tool and connecting through your diagnostic port, you can easily read the stored check engine code. When you see this code return as a Nissan Pathfinder P0105 trouble code, this means there’s an issue with your manifold absolute pressure sensor. This part is otherwise known as your MAP sensor, and it’s a three pin unit mounted in your 3.3 liter Nissan engine.
Today I’ll be showing you how to test the operation of your Nissan pressure sensor to fix your Nissan Pathfinder P0105 trouble code. The test vehicle today is a 1999 Nissan Pathfinder with the VG33DE 3.3 liter engine. This engine is shared throughout many other Nissan vehicles, such as the Frontier as well as the Infiniti QX4.
The specific language behind the Nissan Pathfinder P0105 trouble code is for Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction. This means that this sensor has either gone bad or there’s a problem with the wiring that’s preventing it from operating properly.
What is the Pathfinder MAP Sensor?
This three pin MAP sensor is the way that your engine computer can determine the engine load. By reading the engine vacuum and pressure of the incoming air charge in your intake manifold, the MAP sensor transits this value to your Nissan computer. The Nissan Powertrain Control Module can then translate this signal and deliver the right amount of fuel to the 3.3 liter engine.
When you need to test the Nissan pressure sensor, you will need to use a basic digital multimeter. Using this device you can test the internal resistance of your pressure sensor to determine whether or not the part has gone bad. When this sensor goes bad, you may have other related OBDII trouble codes such as P1105.
Common Nissan issues from a Nissan Pathfinder P0105 trouble code
Because the pressure sensor isn’t operating properly, the engine computer will be working in the blind. This can cause several issues with your Pathfinder, including but not limited to some of these common problems:
- Pathfinder won’t start
- Poor gas mileage
- Bad performance
Where is the Pathfinder MAP Sensor located?
The pressure sensor can be located along the intake manifold and it’s connected to the intake tract that heads to the intake manifold. This part can be found by tracking back the vacuum hose from your intake manifold and barometric pressure sensor. Use the Nissan Pathfinder diagram below to find the pressure sensor and fix your Nissan Pathfinder P0105 trouble code.
Once you’ve found the MAP sensor you will be unplugging this three pin unit to test it. Before you begin insert your Pathfinder key and turn the ignition to the ON position.
What this does is it allows your Pathfinder to send the power and ground signals through your engine harness. Now you are ready to address why you have the Nissan Pathfinder P0105 engine code.
Before you begin checking your manifold absolute pressure sensor, make sure to inspect the barometric pressure lines first. Many times these lines crack or break under the high heat of the engine which can lead to your Nissan Pathfinder P0105 trouble code.
To check your BARO lines use the Pathfinder diagram to the left and locate the dual ports of the sensor. Trace the bottom port or port B to your intake air box. Track back port A or the inner port to the MAP sensor. Lastly check the third port or port C to your intake manifold. If there’s any cracks in the hoses or breaks, replace these hoses first as a precaution.
Testing your Nissan Pathfinder P0105 trouble code
Use the Pathfinder pressure sensor diagram below to check the wiring harness of your Nissan. Unplug the pressure sensor and reference the values at the wiring connector as they relate to the wiring diagram.
The first wire you will be checking at the Pathfinder engine harness is the one that leads to PIN A. Using your multimeter you should have a switched power signal at this wire. Put the black lead of the multimeter on your negative battery terminal and gently probe the wiring harness. Once you have determined that you have power at this wire, you should check PIN C, which should be a ground signal.
If you have power and ground here at these two wires, the Pathfinder pressure sensor should be working properly. Because your Nissan Pathfinder P0105 is for the pressure sensor circuit malfunction the last thing you need to do is measure the signal.
To do this you’ll need to reconnect the MAP sensor and strip away a section of the middle wire, or PIN B in this case. Measure the voltage at this terminal and make sure to keep your hands, tools and clothing free and clear of your engine bay. Now start your VG33DE engine and allow it to warm up at idle if possible.
With the Pathfinder idling this signal should read between .7 and .9 volts of signal. This is a 0-5 volt pressure sensor, and you’ll be gently scaling up the engine speed and measuring the voltage accordingly.
As your engine RPM rises your voltage should also slowly scale upwards. As the engine slows down the voltage should slowly fall back downwards to the idle voltage indicated above. If your pressure sensor does not respond properly, you’ll need a replacement MAP sensor for your Nissan.
This should handle your Nissan Pathfinder P0105 trouble code. Don’t forget to use a OBDII scan tool to erase or clear the code in question. Have a question about your Pathfinder? leave them for me below!