Manifold Absolute Pressure (Map) Sensor
- Ensure ignition is off. To check MAP sensor supply voltage, disconnect electrical connector from MAP sensor. See MAP SENSOR LOCATION table.NOTE: MAP sensor may also be identified using appropriate illustration in the THEORY/OPERATION article. The MAP sensor has a vacuum hose connected to it and may be identified by wire colors. See wiring diagram in the WIRING DIAGRAMS article.MAP SENSOR LOCATION
Application Location Tercel Passenger's Side Of Engine Compartment, On Firewall, Near Wiper Motor - Turn ignition on. Using voltmeter, measure voltage between terminals VC or VCC and E2 of electrical connector on wiring harness. See Fig 1. The VC or VCC and E2 terminals are the 2 outer terminals on all models. Voltage should be within specification. See MAP SENSOR SUPPLY VOLTAGE SPECIFICATIONS table.MAP SENSOR SUPPLY VOLTAGE SPECIFICATIONS
Application Volts Tercel 4.50-5.50 - If supply voltage is not within specification, check wiring circuit. See wiring diagram in the WIRING DIAGRAMS article. If supply voltage is correct, turn ignition off. Reinstall electrical connector on MAP sensor.
- To check MAP sensor output voltage, turn ignition on. Disconnect MAP sensor vacuum hose from intake manifold. Connect voltmeter to terminals PIM and E2 of ECM. See Fig 2. See the ECM LOCATION table.
- Measure and record output voltage under ambient atmospheric pressure. Attach vacuum pump to MAP sensor.
- Apply vacuum in specified increments and measure MAP sensor output voltage drop at each increment. See MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS table. Replace MAP sensor if output voltage drop is not within specification.
MAP SENSOR OUTPUT VOLTAGE DROP SPECIFICATIONS
| Applied Vacuum In. Hg | Output Voltage Drop |
|---|---|
| 3.94 | .3-.5 |
| 7.87 | .7-.9 |
| 11.81 | 1.1-1.3 |
| 15.75 | 1.5-1.7 |
| 19.69 | 1.9-2.1 |