Celica L4-96.8 1587cc 1.6L DOHC (4A-FE) (1990)
Manifold Pressure/Vacuum Sensor: Testing and Inspection
Component Inspection
1. Disconnect the connector to the MAP Sensor.
2. Turn the ignition switch ON.
3. Using a voltmeter, measure the voltage between terminals VCC and E2 of the sensor harness connector.
Checking MAP Sensor Voltage
4. Voltage should measure 4.5 - 5.5 volts.
5. If not as specified, test wiring between ECU and MAP Sensor. If no problems are found, replace the ECU and continue testing procedure.
6. With ignition switch turned ON, disconnect the vacuum hose from the MAP Sensor.
7. Connect a voltmeter to terminals PIM and E2 at the ECU and measure the voltage with zero vacuum applied.
Testing MAP Sensor Voltage Drop
8. Using a handheld vacuum pump, apply vacuum to the MAP Sensor in increments of 3.94 in.Hg. Compare the Voltage Drop Chart to the applied
vacuum quantities.
MAP Sensor Voltage Drop Chart
9. If readings are not as specified, replace the MAP Sensor.
10. Disconnect the voltmeter and vacuum pump.
11. Reconnect vacuum hoses and connector.