P0453

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 voltage goes above a predetermined value, diagnostic trouble code (DTC) P0453 will set.

CONDITIONS FOR RUNNING THE DTC
The key is ON.

CONDITIONS FOR SETTING THE DTC
^ The FTP sensor voltage is more than 4.9 volts.
^ All conditions present for more than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test ran and failed.
^ The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The malfunction indicator lamp (MIL) will turn OFF after 3 consecutive ignition cycles in which the diagnostic runs without a fault.
^ A history DTC will clear after 40 consecutive warm up cycles without a fault.
^ Use a scan tool in order to clear the DTCs.

TEST DESCRIPTION

DTC P0453 - Steps 1-4:

DTC P0453 - Steps 5-15:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the condition is present.
4. This step tests the signal circuit of the FTP sensor.
5. This step tests the ground circuit of the FTP sensor.
6. This step tests the 5-volt reference circuit of the FTP sensor. If the DMM displays a voltage more than 5 volts, repair the short to voltage.