P0452

CIRCUIT DESCRIPTION
The control module monitors the fuel tank pressure (FTP) sensor signal in order to detect vacuum decay and excess vacuum during the enhanced evaporative emission (EVAP) diagnostic. The control module supplies a 5-volt reference and ground to the sensor. The FTP sensor signal voltage increases as the FTP decreases, negative pressure or vacuum, high voltage. The FTP sensor signal voltage decreases as the FTP increases, positive pressure, low voltage. When the FTP sensor signal goes below a predetermined value, DTC P0452 will set.

CONDITIONS FOR RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC
^ The FTP sensor voltage is less than 0.1 volt.
^ All conditions present for greater than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The control module will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
^ A current DTC, Last Test Failed, clears when diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by or any other emission related diagnostic.
^ Use the scan tool in order to clear the MIL and the DTC.

TEST DESCRIPTION

Steps 1-4:

Steps 5-13:

The number below refers to the step number on II diagnostic table.
5. This step tests for the proper operation of the circuit in the high voltage range.