P0453
DTC P0453
CIRCUIT DESCRIPTION
The DTC P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage diagnostic monitors the FTP sensor voltage. The evaporative emission (EVAP) control system prevents the emission of the fuel vapors. The fuel vapor generated in the fuel tank while driving or idling enters the EVAP canister where a charcoal element absorbs and stores the fuel vapor. When certain engine operating conditions are met the powertrain control module (PCM) purges the EVAP canister of stored vapors by turning ON the EVAP canister purge valve.
Emissions laws require that the PCM detect any leakage within the EVAP system. The PCM monitors the EVAP system for leaks by controlling and observing the vapor pressures in the EVAP system. The FTP sensor is used to detect any unexpected pressure in the EVAP system. The PCM supplies a 5-Volt reference, an electrical ground, and a signal return circuit that has a 5-Volt bias. The FTP sensor contains a silicon based chip that changes electrical resistance when pressure is applied. The sensor converts the positive or the negative pressure into an electrical signal and sends the signal to the PCM.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0453 Fuel Tank Pressure (FTP) Sensor Circuit High Voltage
CONDITIONS FOR RUNNING THE DTC
- The engine is running.
- The intake air temperature (IAT) sensor is between 4°C (40°F) and 35°C (95°F).
- DTC P0453 runs once per drive cycle when the above conditions have been met.
CONDITIONS FOR SETTING THE DTC
The FTP sensor signal indicates more than 15 mm Hg (8.0 in H2O) for 7 seconds.
ACTION TAKEN WHEN THE DTC SETS
- The PCM illuminates the malfunction indicator lamp (MIL).
- 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.
- Use the scan tool Clear DTC Information function.
DIAGNOSTIC AIDS
- If a DTC P0453 is intermittent, road test the vehicle while observing the FTP sensor with a scan tool. A momentary reading of more than 4.50 volts may indicate an open in the sensor input or ground circuit.
- If a DTC P0453 is intermittent, driving the vehicle under the conditions outlined in the Inspection/Maintenance (I/M) section can verify whether the fault is present. Refer to Inspection/Maintenance (I/M) Evaporative Emission (EVAP) System Set Procedure. Evaporative Emission (EVAP) System Set Procedure
- An intermittent malfunction may be caused by a fault in the sensor electrical circuit. Inspect the wiring harness and the components for an intermittent condition.
- The information included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC first set.
TEST DESCRIPTION
Step 1 - Step 13:
Step 14 - Step 17:
The numbers below refer to the step numbers on the diagnostic table.
1. The Diagnostic System Check - Vehicle 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. This step determines if a FTP sensor malfunction is present. The input signal of the FTP sensor should indicate atmospheric pressure with the fuel tank filler cap removed. The fuel tank pressure sensor voltage will vary with atmospheric pressure. A typical FTP reading at sea level is between 3.5-3.8 volts.
6. The FTP sensor input circuit carries a 5 volt bias that can be measured with the DMM. If the measured voltage is near zero there is an open or a faulty PCM.
9. This step checks for an open in the FTP sensor ground circuit.
16. The EVAP system diagnostic can be monitored on the scan tool under the I/M System Information selection. When the EVAP test displays a YES status, indicating that the system diagnostic is completed, check for DTC P0453 in the Last Test Failed screen of the scan tool. If there is no DTC P0453 displayed the EVAP system diagnostic has run and passed, indicating that no malfunction was present this time. DTCs MUST be cleared in order to view the Current Status of the system diagnostics being performed. Do not forget that the I/M System Information tests only indicate that the test has run, not if the test passed or failed. The Last Test Failed screen must be checked for related DTCs in order to determine the outcome of the diagnostic test involved.