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 THEORY/OPERATION article. The MAP sensor has a vacuum hose connected to it and may be identified by wire colors. See appropriate wiring diagram in 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, check MAP sensor supply voltage between terminals VC or VCC on wiring harness side of electrical connector for MAP sensor. See Fig 1. The VC or VCC and E2 terminals are the 2 outer terminals on all models. DO NOT use the center terminal.
- The MAP sensor supply voltage should be 4.5-5.5 volts. If MAP sensor supply voltage is not within specification, check wiring circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. If MAP sensor supply voltage is within specification, turn ignition off. Reinstall electrical connector on MAP sensor.
- To check MAP sensor output voltage, turn ignition on. Disconnect vacuum hose for MAP sensor from intake manifold. Connect voltmeter between terminals PIM and E2 on Engine Control Module (ECM). See Figure. See ECM LOCATION and TERMINAL & WIRE COLOR IDENTIFICATION table.ECM LOCATION
Model Location Tercel Behind Glove Box TERMINAL & WIRE COLOR IDENTIFICATIONApplication & Terminal Wire Color PIM Pink E2 Brown - 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 |