PCM monitors fuel tank pressure sensor signal to detect
vacuum decay and excess vacuum during the enhanced EVAP diagnostic.
Fuel tank pressure sensor measures the difference between air pressure
(or vacuum) in the tank and the outside air pressure. PCM applies 5-
volt reference and ground to the sensor. Sensor will return a signal
voltage between 0.1-4.9 volts. If PCM detects a fuel tank pressure
sensor signal that is excessively low, DTC will set.
Symptoms
You likely won't notice any drivability problems.
Causes
Fuel tank pressure sensor signal is less than 0.1 volt.
Solutions
Check for poor terminal connections at fuel tank pressure
sensor connector.
Check for shorts.
Check for damaged harness.
Replace fuel tank pressure sensor.
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Dan SAVING THE WORLD ONE BONNEVILLE AT A TIME
P0452
