Page 314 - Foton Workshop Manual - Tunland (AT)
P. 314
04-168 DIAGNOSTICS - ENGINE CONTROL SYSTEM
P221，P222，P1943-ATMOSPHERIC PRESSURE SENSOR FAULT
P221 - ATMOSPHERIC PRESSURE SENSOR CIRCUIT -VOLTAGE
IS ABOVE NORMAL OR SHORTED TO HIGH VOLTAGE POWER
SUPPLY
04 P222 - ATMOSPHERIC PRESSURE SENSOR CIRCUIT -VOLTAGE
IS BELOW NORMAL OR SHORTED TO HIGH VOLTAGE POWER
SUPPLY
P1943 - AMBIENT AIR DENSITY - DATA IS VALID BUT ABOVE
NORMAL OPERATING RANGE - LOWEST SEVERITY LEVEL
Description
1 . A ambient pressure sensor can respond to changes in atmospheric pressure.
Atmospheric pressure will vary depending on the current altitude of the engine.
The ambient pressure sensor has a 5V supply circuit, a sensor signal voltage
circuit and a loop circuit.The ambient pressure sensor provides a signal to the
engine control module (ECM) via an atmospheric pressure sensor signal circuit.
The signal voltage of the sensor will vary according to atmospheric pressure.
When the vehicle works at high altitude, the ECM detects low signal voltage.
When at low altitude, the ECM will detect a high signal voltage.
Circuit Diagram
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