Pressure Sensor

Sensor is mounted to right center of firewall. To test pressure sensor on vehicle, turn ignition on. Connect voltmeter between ground and indicated ECM connector terminal (backprobe ECM terminal). See PRESSURE SENSOR OUTPUT VOLTAGE (ON-VEHICLE) table.
If voltage is not within specification, see Code 31 or 32 in TESTS W/CODES article in the ENGINE PERFORMANCE Section. To test pressure sensor off vehicle, see PRESSURE SENSOR OUTPUT VOLTAGE (OFF-VEHICLE) table. If voltage is not within specification, replace pressure sensor.

PRESSURE SENSOR OUTPUT VOLTAGE (ON-VEHICLE)

Altitude (Feet)

Vacuum (In. Hg)

⁽¹⁾⁽²⁾ Output Voltage

3.6-4.4

1000

3.5-4.2

2000

3.4-4.1

3000

3.2-4.0

4000

3.1-3.8

5000

3.0-3.7

6000

2.9-3.6

7000

2.8-3.4

8000

2.7-3.3

9000

2.6-3.2

10,000

2.5-3.1

⁽¹⁾	Pressure sensor output voltage is tested at ECM connector. See ECM LOCATION table. Before testing pressure sensor output voltage, ensure ECM supply voltage is 4.75-5.52 volts at A23 Gray/Red wire terminals of ECM connector.

⁽²⁾	Output voltage is checked at A22 Gray/Green wire terminals of ECM connector.

PRESSURE SENSOR OUTPUT VOLTAGE (OFF-VEHICLE)

Altitude (Feet)

Vacuum (In. Hg)

⁽¹⁾⁽²⁾ Output Voltage

3.4-3.8

1000

3.3-3.7

2000

3.1-3.6

3000

3.0-3.5

4000

2.9-3.3

5000

2.8-3.2

6000

2.7-3.1

7000

2.6-3.0

8000

2.5-2.9

9000

2.4-2.8

10,000

2.3-2.7

⁽¹⁾	Pressure sensor output voltage is tested with three 1.5-volt batteries connected in series. Positive lead is connected to Gray/Red wire terminal. Connect negative lead to Gray/Yellow wire terminal.

⁽²⁾	Output voltage is checked at Gray/Green wire terminal of pressure sensor connector.