Barometric Pressure Sensor: Testing and Inspection

BAROMETRIC PRESSURE SENSOR

OPERATION
- The barometric pressure sensor functions to convert the barometric pressure to voltage, and to input that voltage (as signals) to the engine control module. The engine control module based upon those signals, then corrects the amount of fuel injection, etc.
- The 5 V power supply within the engine control module is supplied to the barometric pressure sensor; it passes through the circuitry within the sensor, and is grounded at the engine control module.
- The barometric-pressure sensor output voltage is supplied to the engine control module in proportion to the barometric pressure (absolute pressure).

TROUBLESHOOTING HINTS
Hint 1:
If there is a malfunction of the barometric pressure sensor, driveablity of the vehicle will become worse, particularly at high altitudes.
Hint 2:
If, during high-speed driving, there is a noticeable sharp drop of the displayed pressure of the barometric-pressure sensor, check for clogging of the air cleaner.




INSPECTION

Using Scan Tool

HARNESS INSPECTION





STEP 1. Check for continuity in the ground
- Volume air flow sensor connector: Disconnected

OK: GO TO STEP 2
NG: Repair the harnesses. (A5 - 92)





STEP 2. Check for an open or short-circuit between the barometric pressure sensor and the engine control module.
- Volume air flow sensor connector: Disconnected
- Engine control module connector: Disconnected

OK: GO TO STEP 3
NG: Repair the harnesses. (A1 - 81, A2 - 85)





STEP 3. Measure the power supply voltage of the barometric pressure sensor.
- Volume air flow sensor connector: Disconnected
- Ignition switch: ON
- Engine control module connector: Connected

Voltage (V): 4.8 - 5-2

OK: STOP
NG: Replace the engine control module.