P0453

CIRCUIT DESCRIPTION
The fuel tank pressure (FTP) sensor measures the difference between the air pressure or vacuum in the evaporative emission (EVAP) system, and the outside air pressure. The control module supplies a 5-volt reference and a low reference circuit to the FTP sensor. The FTP sensor signal circuit voltage varies depending on EVAP system pressure or vacuum. If the FTP sensor signal voltage goes above a calibrated value, this DTC sets.

DTC P0453:

The table illustrates the relationship between FTP sensor signal voltage and the EVAP system pressure/vacuum.

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 are present for more 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 records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

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

Steps 1-3:

Steps 4-15:

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.