Pressure Sensor (SOHC)

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 bench test pressure sensor, see PRESSURE SENSOR OUTPUT VOLTAGE (OFF-VEHICLE) table. If voltage is not within specification, replace pressure sensor.

PRESSURE SENSOR OUTPUT VOLTAGE (ON-VEHICLE)

Altitude (Ft.)

Vacuum (In. Hg)

⁽¹⁾ Output Voltage

SOHC

3.5-4.1

1000

3.4-4.0

2000

3.2-3.8

3000

3.1-3.7

4000

3.0-3.6

5000

2.9-3.5

6000

2.8-3.3

7000

2.7-3.2

8000

2.6-3.1

9000

2.5-3.0

10,000

2.4-2.9

⁽¹⁾	Check output voltage at ECM connector terminal B2 (Light Green/Red wire - SOHC). See ECM LOCATION table. Before checking output voltage, ensure ECM supply voltage is 4.75-5.25 volts at ECM connector terminal B1 (Light Green wire - SOHC).

PRESSURE SENSOR OUTPUT VOLTAGE (OFF-VEHICLE)

Altitude (Ft.)

Vacuum (In. Hg)

⁽¹⁾⁽²⁾ Output Voltage

SOHC

0-2000

28-30

2.9-4.2

2001-5000

25-28

2.7-4.0

5001-8000

22-25

2.5-3.8

8001-10,000

20-22

2.0-3.3

⁽¹⁾	Pressure sensor output voltage is tested with three 1.5-volt batteries connected in series. Positive lead is connected to Light Green wire terminal (SOHC). Connect negative lead to Light Green/Black wire terminal SOHC).

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