Component Inspection

CHECK BRAKE BOOSTER PRESSURE 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 per the following.

TERMINAL VOLTAGE REFERENCE CHART

ECM
Connector	+	-
Connector	Terminal	Terminal
F101	39	36

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 depends 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.

ATMOSPHERIC PRESSURE REFERENCE 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.

VOLTAGE REFERENCE 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

Is the inspection result normal?

YES: GO TO 2.

NO: Replace brake booster pressure sensor.

Fig 1: Manifold Absolute Pressure Sensor Voltage Graph

Courtesy of NISSAN NORTH AMERICA, INC.

CHECK BRAKE BOOSTER PRESSURE SENSOR-II

Turn ignition switch OFF.
Remove brake booster pressure sensor with its harness connected.
Connect the hose of vacuum pump (A) to brake booster pressure sensor (1).
Turn ignition switch ON.

Fig 2: Connecting Hose Of Vacuum Pump To Brake Booster Pressure Sensor
Courtesy of NISSAN NORTH AMERICA, INC.

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

TERMINAL CONTINUITY REFERENCE CHART

ECM
+		-
Connector	Terminal	Connector	Terminal
F101	39	F101	36

Check that the difference of the voltage when engine is stopped and that when negative pressure is applied with vacuum pump is within the following limits.

VOLTAGE REFERENCE CHART

Vacuum	Voltage difference (V)
-40kPa (-300mmHg)	1.5 - 2.0
-53.3kPa (-400mmHg)	2.0 - 2.6
-66.7kPa (-500mmHg)	2.6 - 3.2
-80kPa (-600mmHg)	3.2 - 3.8

Is the inspection result normal?

YES: INSPECTION END

NO: Replace brake booster pressure sensor.