P0452

CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) 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 PCM supplies a 5-volt reference and ground to the sensor. The FTP sensor signal voltage increases as the fuel tank pressure decreases (negative pressure or vacuum, high voltage). The FTP sensor signal voltage decreases as the fuel tank pressure 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 key is ON.

CONDITIONS FOR SETTING THE DTC
^ The fuel tank pressure sensor voltage is less than 0.1 volts.
^ All the conditions are present for more than 5 seconds

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) when the diagnostic runs and fails.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

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 the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
^ Use a scan tool in order to clear the MIL and the DTC.

TEST DESCRIPTION

Steps 1-4:

Steps 5-14:

The number below refers to the step number on the diagnostic table.
5. If the FTP sensor voltage is near 5 volts, the FTP sensor signal and the 5-volt reference circuits are OK from the body pass-through connector to the PCM.