Manifold Absolute Pressure (MAP) Sensor
- A malfunction in the manifold absolute pressure sensor circuit will set diagnostic trouble Codes 31 and/or 32. For testing procedures, see TESTS W/CODES article in this section. Use the following procedure to diagnose MAP sensor. If driveability problems exist, MAP sensor failure is suspected and no Codes 31 and/or 32 is set, disconnect MAP sensor connector. If driveability improves, replace MAP sensor.
- 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 . Reading should be approximately 5 volts.
- Disconnect vacuum hose at MAP sensor. Install hand-held vacuum pump. Turn ignition on. Check signal voltage at designated wire terminal of MAP sensor. See MAP SENSOR WIRE TERMINAL IDENTIFICATION .
- Apply vacuum, and note change in signal voltage. As vacuum reading changes, signal voltage should change. Reading should be about 1-1.5 volts at high vacuum (idle position) to 4-4.5 volts at low vacuum (full throttle position).
MAP SENSOR WIRE TERMINAL IDENTIFICATION
| Application | Supply Voltage Wire Color | Signal Voltage Wire Color |
|---|---|---|
| Prizm & Prizm LSi | Yellow | Light Green/Red |