P0453
CIRCUIT DESCRIPTION
The DTC P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage diagnostic monitors the function of the FTP sensor circuit. Emission laws require that the powertrain control module (PCM) detect any leakage within the EVAP system. The PCM tests the EVAP system for leaks by monitoring the vapor pressures in the fuel tank with the FTP sensor. The FTP sensor contains a silicon based chip that changes electrical resistance when pressure is applied. The PCM supplies a 5-volt reference, an electrical ground, and a signal return circuit that has a 5-volt bias. The FTP sensor signal voltage varies from a minimum of about 0.2 volts with negative pressure in the fuel tank, to a maximum of more than 4 volts with positive pressure in the fuel tank.
CONDITIONS FOR RUNNING THE DTC
- The engine coolant temperature is -8 to +110°C (18-230°F).
- The intake air temperature is -14 to +70°C (7-158°F).
- The engine has been running at idle for at least 2 minutes.
CONDITIONS FOR SETTING THE DTC
The fuel tank pressure is higher than 49.5 mm Hg (-26.5 in H2O).
OR
The fuel tank pressure sensor signal voltage is greater than 4.5 volts.
ACTION TAKEN WHEN THE DTC SETS
- The PCM illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with the fault active.
- The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.
CONDITIONS FOR CLEARING THE MIL/DTC
- The MIL turns OFF after 3 consecutively passing trips without a fault present.
- A history DTC clears after 40 consecutive warm-up cycles without a fault.
- Perform the scan tool Clear DTC Information function in order to clear the DTC.
TEST DESCRIPTION
Steps 1-4:
Steps 5-7:
Steps 8-10:
Steps 11-14:
The numbers below refer to the step numbers in the diagnostic table.
1. The Diagnostic System Check-Computers and Control Systems prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.
2. If a DTC P0123 is also set there is a fault in the sensor ground circuit or the PCM.
3. If a DTC P2027 is also set there is a fault in the sensor ground circuit or the sensor.
4. The FTP sensor reading indicated on the scan tool will vary with the surrounding barometric pressure.
6. The voltage measured with the DMM will vary with the surrounding barometric pressure.
13. Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P0453 diagnostic can be monitored on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If DTC P0453 appears in the Not Ran Since Code Cleared list, the P0453 diagnostic has not yet run. When DTC P0453 does not appear in the Not Ran Since Code Cleared list, the P0453 diagnostic has run. If the MIL is NOT illuminated and there is no Pending DTC Status in DTC Information, the P0453 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. The DTC Information screen must be checked for Current or Pending status in order to determine the outcome of the diagnostic test involved.