Page 764 - Workshop Manual - Tunland (2017)

04-78 DIAGNOSTICS - ENGINE CONTROL SYSTEM

04
P221，P222，P1943-ATMOSPHERIC PRESSURE SENSOR FAULT
P221 - ATMOSPHERIC PRESSURE SENSOR CIRCUIT -VOLTAGE
IS ABOVE NORMAL OR SHORTED TO HIGH VOLTAGE POWER

SUPPLY
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