1996 Nissan Maxima 3.0 P0105 P1105

Both fault codes point to the absolute pressure sensor. The absolute pressure sensor is connected to the MAP / BARO switch solenoid valve by a vacuum hose. The sensor detects ambient barometric pressure and intake manifold pressure and sends a voltage signal to the ECM. As pressure increases, voltage rises. The sensor is not used as an input to control the engine management system. It is used only for on-board diagnosis. Therefore you can have fault codes with no drivability complaint.

You can see both the sensor and switching solenoid have been replaced. The fault codes remained.


I went directly to the sensor to backprobe the connector with the key ON and engine OFF. The first wire I tested was the 5 volt reference. The reading I obtained was 4.35 volts. Too low for a 5 volt reference. I wiggled the harness and the voltage changed accordingly. Next I cut the harness sheathing back to reveal damaged wires. 1 completely broken and the others with broken insulation. The harness to the sensor has a very sharp bend in it. Over time the wires degraded and finally failed. A quick harness repair and the fault codes were gone.