P0452
DTC P0452Circuit Description
The powertrain control module (PCM) monitors the fuel tank pressure (FTP) sensor signal in order to detect vacuum decay and excess vacuum during the enhanced evaporative emission (EVAP) diagnostic. The PCM supplies a 5-volt reference and ground to the sensor. The FTP sensor signal voltage increases as the fuel tank pressure decreases, negative pressure or vacuum, high voltage. The FTP sensor signal voltage decreases as the fuel tank pressure increases, positive pressure, low voltage. When the FTP sensor signal goes below a predetermined value, diagnostic trouble code (DTC) P0452 will set.
Conditions for Running the DTC
The Key is ON.
Conditions for Setting the DTC
- The FTP sensor voltage is less than 0.1 volt.
- All conditions present for more than 5 seconds.
Action Taken When the DTC Sets
- The PCM will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test ran and failed.
- The PCM will store conditions which were present when the DTC set as Freeze Frame/Failure Records data.
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
The numbers below refer to the step numbers on the diagnostic table.
2. This step verifies that the condition is present.
4. This step tests the 5-volt reference of the FTP sensor.
5. This step tests if another component is causing the 5-volt reference circuit condition. If the voltage increases when a component is disconnected, replace that component.
6. If the scan tool displays 5 volts, the FTP sensor signal circuit, the FTP sensor 5-volt reference circuit, and the PCM are OK.
