Component Inspection

WARNING: This page is about a different car, the 2011 Infiniti FX50. However, it is still accessible from the selected car via links, so may be relevant.

CHECK MAP SENSOR-I

Turn ignition switch OFF.
Start engine and warm it up to normal operating temperature.
Turn ignition switch OFF, wait at least 5 seconds and then turn ON.

Check the voltage between ECM harness connector terminals as follows.

VOLTAGE REFERENCE CHART

ECM
+		-
Connector	Terminal	Connector	Terminal
F111	69	F111	70

NOTE:

To avoid the influence of intake manifold vacuum, check the voltage 1 or more minutes past after engine is stopped.
Because the sensor is absolute pressure sensor, output value may differ depending on atmospheric pressure and altitude.

Measure the atmospheric pressure.

NOTE: As the atmospheric pressure described on the synoptic chart is the value at sea level, compensate the pressure with the following chart.

COMPENSATED PRESSURE SPECIFICATION CHART

Altitude (m)	Compensated pressure (hPa)
0	0
200	-24
400	-47
600	-70
800	-92
1000	-114
1500	-168
2000	-218

Check the manifold absolute pressure sensor value corresponding to the atmospheric pressure.

ATMOSPHERIC PRESSURE SPECIFICATION CHART

Atmospheric pressure (hPa)	Voltage (V)
800	3.1 - 3.7
850	3.3 - 3.9
900	3.5 - 4.1
950	3.8 - 4.3
1000	4.0 - 4.6
1050	4.2 - 4.8

Fig 1: Atmospheric Pressure And Voltage Graph

Courtesy of NISSAN MOTOR CO., U.S.A.

Is the inspection result normal?

YES: GO TO 2.

NO: Replace MAP sensor. Refer to "EXPLODED VIEW ".

CHECK MAP SENSOR-II

Start engine and let it idle.
Check intake manifold vacuum.

Check the voltage between ECM harness connector terminals as per the following.

VOLTAGE REFERENCE CHART

ECM
+		-
Connector	Terminal	Connector	Terminal
F111	69	F111	70

Confirm the difference of the voltage when engine is stopped and at idling is within the values shown in the following chart.

VOLTAGE REFERENCE CHART

Intake manifold vacuum [kPA (mmHg)]	Voltage difference (V)
-40 (-300)	1.5 - 2.0
-53.3 (-400)	2.0 - 2.6
-66.7 (-500)	2.6 - 3.2
-80 (-600)	3.2 - 3.8

Is the inspection result normal?

YES: INSPECTION END

NO: Replace MAP sensor. Refer to "EXPLODED VIEW ".