Manifold Absolute Pressure (Map) Sensor

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

MAP 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⁾	MAP sensor output voltage tested with coupler connected to ECM. Before testing MAP sensor output voltage, ensure ECM supply voltage is 4.75-5.25 volts at connector terminal A23 (Gray/Red wire) and terminal A24 (Gray/Yellow wire)

⁽²⁾	Output voltage checked at ECM connector terminal A22 (Gray/Green wire) and terminal A24 (Gray/Yellow wire) Start engine, if possible, see if output voltage varies.

MAP 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⁾	MAP sensor output voltage is tested with three 1.5-volt batteries connected in series (output 4.5-5.0 volts). Positive lead of batteries is connected to VIN terminal. Negative lead of batteries is connected to ground terminal. Check output voltage between VOUT terminal and ground.

⁽²⁾	Voltage should reduce when up to 15 in. Hg of vacuum is applied to MAP sensor.