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Manifold Absolute Pressure (MAP) Sensor

  1. The MAP sensor is located on firewall. With ignition on, check supply voltage from ECM to MAP sensor on designated wire terminal. See MAP SENSOR WIRE TERMINAL IDENTIFICATION  table. Voltage should be approximately 5 volts.
  2. Disconnect vacuum hose at MAP sensor and install hand-held vacuum pump. Turn ignition on. Check signal voltage at designated wire terminal of MAP sensor. See MAP SENSOR WIRE TERMINAL IDENTIFICATION  table.
  3. As vacuum reading changes, voltage should change. Reading should vary from approximately 1 to 1 1/2 volts at high vacuum and to 4 to 4 1/2 volts at low vacuum. Reading should change evenly as vacuum changes and will vary with altitude. See MAP SENSOR VOLTAGE SPECIFICATIONS  table.
MAP SENSOR WIRE TERMINAL IDENTIFICATION

Application Supply Voltage Wire Color Signal Voltage Wire Color
Metro Light Green Light Green/Red
MAP SENSOR VOLTAGE SPECIFICATIONS

Altitude Feet (Meters) Signal Voltage
Below 1,000 (304) 3.8-5.5
1,000-2,000 (304-610) 3.6-5.3
2,000-3,000 (610-914) 3.5-5.1
3,000-4,000 (914-1219) 3.3-5.0
4,000-5,000 (1219-1524) 3.2-5.8
5,000-6,000 (1524-1829) 3.0-4.6
6,000-7,000 (1829-2133) 2.9-4.5
7,000-8,000 (2133-2438) 2.8-4.3
8,000-9,000 (2438-2473) 2.6-4.2
9,000-10,000 (2473-3048) 2.5-4.0