P1105 Nissan 3.3L – Test a Pathfinder MAP Sensor
The dreaded P1105 Nissan OBDII trouble code refers to the Manifold Absolute Pressure sensor in your 3.3 liter Nissan Pathfinder, and can also be called the Barometric sensor or Pathfinder MAP Sensor. The specific Nissan terminology for this trouble code is Manifold Absolute Pressure/Barometric Pressure Switch Solenoid Valve Fault.
It can be confusing to the average shadetree mechanic, who might think the two are the same when in fact they are separate. We’ve found that this P1105 Nissan trouble code is caused mostly by the MAP sensor itself. The test vehicle we’ll be showing you today is a 1997 Nissan Pathfinder with the VG33DE engine. Many other Nissan and Infiniti vehicles share this same engine, like the Frontier and QX4. Despite some of these engines being 3.5 liter, the testing procedure is largely the same for this MAP sensor.
Symptoms of a bad MAP sensor
- Poor fuel economy
- Sluggish throttle
- Car won’t start
What could be wrong?
Usually the baro or MAP sensor has become contaminated or simply failed, although other issues may prevent your MAP sensor from working correctly. The vacuum line that runs to the MAP sensor may be clogged or torn, leading to a lack of pressure.
There is a metal tube that runs under the intake manifold that this vacuum line runs to, if there is no damage to the vacuum hose itself, check for a rusted pipe.
Where is my MAP sensor?
The MAP sensor and BARO sensor are part of your intake tract that leads to your throttle body from your airbox.
To test this unit, you will be unplugging the manifold absolute pressure (MAP) sensor and testing for power and signal. This MAP sensor part number is 22365-9E02A, and it’s a three pin weatherproof connector that you’ll be testing from.
Before you begin testing your MAP sensor, ensure that the BARO sensor shown above is working correctly. This BARO sensor switches when power is applied, allowing the air charge to flow to the pressure sensor (MAP).
It’s easy to test your Pathfinder MAP Sensor but it’s even easier to determine whether or not your BARO sensor is working correctly.
How to Check your BAROMETER vacuum lines
In the diagram above, you will note the three vacuum ports that lead away from the sensor and to different areas of the engine. Port B or the outer most port located under the baro sensor leads to the factory air box as incoming air.
Port A on the BARO sensor leads to the manifold absolute pressure (MAP) sensor and lastly Port C goes back to the intake manifold. Check the vacuum hoses here for any signs of wear, cracking or clogging. Replace or shorten if you feel as though there is damage.
Next you will be using a power probe, or simply raw wires to the BARO sensor to see if it clicks over. Attach wires to your battery, and a fuse is recommended inline to the positive terminal. Connect to the BARO sensor, and you should hear it click over which means it’s operating correctly.
To check the operation of the BARO sensor, you will need a Mity Vac or similar vacuum testing device. Connect it to the ports shown below and test with power applied to the BARO sensor, and without.
- With battery power and ground applied – Air will travel from ports A and B and should NOT pass through B and C.
- Without battery power and ground applied – Air will NOT travel from ports A and B but will pass through B and C.
Test your MAP Sensor
Unplug this connector, and you will be testing on the engine harness side to determine if the MAP sensor is receiving power, low reference (Ground) and transmitting the right signals.
Now with all that taken care of, you should now know that your BARO sensor is working correctly, which means it’s time to test your MAP sensor now. Referencing the image above, you will be testing the pins on the MAP sensor connector, not the MAP sensor itself.
Using your multimeter, check PIN A for a switched power source by turning the key to the “ON” position. Do not start the engine. With the black lead of your multimeter on the negative terminal of the battery, the MAP sensor CONNECTOR should read switched power from the A pin position.
Next to check in the procedure to Test your MAP Sensor, is PIN C or the low reference signal wire (ground). Connect the positive lead to the battery and the black lead to the MAP sensor CONNECTOR in the PIN C position. You should see a ground signal here, which means your MAP sensor has power and ground.
The middle pin on your 3.3L Nissan MAP sensor is the Signal wire, and you will be reconnecting the MAP engine harness to the MAP sensor for this test. Backprobe the MAP sensor connector to see what the MAP sensor is reporting to the ECU. At idle you should see close to 1 volt of signal.
Using your Mighty Vac or similar vacuum testing device, apply pressure or blow into the port of the MAP sensor with the signal wire probed. You should see the voltage rise with the increase in pressure accordingly to the ECU.
If this test checks out okay, and you still have an issue, there may be a break between your MAP sensor signal wire and the ECU in your 3.3L Nissan. This will correct and clear your P1105 Nissan OBDII trouble code, if you have any questions please let me know below! That does it for our how to test your MAP Sensor in a 3.3 liter Nissan, Thanks for reading!