P0452
DTC P0452
Circuit Description
The control module monitors the fuel tank pressure (FTP) sensor signal in order to detect vacuum decay and excess vacuum during the enhanced evaporative emissions (EVAP) diagnostic. The control module supplies a 5-volt reference and ground to the sensor. The FTP sensor signal voltage increases when the fuel tank pressure decreases, indicating a negative pressure or vacuum, or high voltage. The FTP sensor signal voltage decreases when the fuel tank pressure increases, indicating positive pressure, or low voltage. When the FTP sensor signal goes below a predetermined value, DTC P0452 will set.
DTC Descriptors
This diagnostic procedure supports the following DTC. DTC P0452 Fuel Tank Pressure (FTP) Sensor Circuit Low Voltage
Conditions for Running the DTC
- The engine is running.
- DTC P0452 runs continuously.
Conditions for Setting the DTC
- The fuel tank pressure sensor voltage is less than 0.1 volts.
- All conditions are present for greater 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 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.
- Clear the MIL and the DTC with a scan tool.
Test Description
The number below refers to the step number on the diagnostic table.
5. If the FTP sensor voltage is near 5 volts, the FTP sensor signal and the 5-volt reference circuits are OK from the body wiring harness connector to the PCM.
