P0453

CIRCUIT DESCRIPTION
The Fuel Tank Pressure (FTP) sensor measures the pressure or the vacuum in the fuel tank. The Powertrain Control Module (PCM) provides the sensor with a reference voltage, a signal circuit, and a ground. The sensor returns a signal voltage to the PCM relative to the pressure in the fuel tank. The PCM should see a signal voltage increase when the pressure in the tank decreases due to more vacuum). When the pressure in the tank increases due to less vacuum, the PCM should see a signal voltage decrease. The PCM uses the sensor signal in order to test the integrity of the EVAP system. If the PCM detects a signal voltage that is too high, DTC P0453 will set.

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
The fuel tank pressure sensor voltage is more than 4.9 volts for at least 1 second.

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 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 1-6:

Steps 7-14:

The numbers below refer to the step numbers on the diagnostic table.
7. This step attempts to duplicate the condition.