P0453

DTC P0453: Fuel Tank Pressure (FTP) Sensor Circuit High Voltage

Wiring Diagram:

System Description
The Evaporative emission (EVAP) system includes the following components:
^ Fuel tank
^ EVAP emission vent solenoid
^ Fuel tank pressure sensor
^ Fuel pipes and hoses
^ Fuel vapor lines
^ Fuel cap
^ EVAP emission canister
^ Purge lines
^ EVAP emission canister purge valve
^ EVAP emission service port

The EVAP emission system is checked by applying vacuum to the EVAP emission system and monitoring for a vacuum decay. The Engine Control Module (ECM) monitors the vacuum level through the fuel tank pressure sensor signal.

At the appropriate time, the EVAP emission canister purge valve and the EVAP emission vent solenoid are turned ON, allowing the engine to draw a small vacuum on the entire EVAP emission system. After the desired vacuum level has been achieved, the EVAP emission canister purge valve is turned OFF, sealing the system.

The ECM supplies a 5 volt reference signal and a ground to the fuel tank pressure sensor. The fuel tank pressure sensor sends a voltage signal back to the ECM relative to the fuel tank pressure. The voltage signal will vary from 0.3 to 4.7 V.

Conditions for Setting the DTC
Sensor output is greater than 4.95 V.

Action Taken When the DTC Sets
^ The Malfunction Indicator Lamp (MIL) will illuminate.
^ The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and Failure Records buffers.
^ A history Diagnostic Trouble Code (DTC) is stored.

Conditions for Clearing the MIL/DTC
^ The MIL will turn OFF after four 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.
^ The DTC(s) can be cleared using the scan tool.

Diagnostic Aids
If a DTC P0453 cannot be duplicated, the information included in the Freeze Frame data can be useful. Use the scan tool information data to determine the status of the DTC. If the DTC occurs intermittently, using the diagnostic table may help isolate the problem.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
1. The On-Board Diagnostic (OBD II) System Check prompts the technician to complete some basic checks and to store the Freeze Frame and Failure Records data on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred.
The information is then stored on the scan tool for later reference.
2. With the fuel tank pressure sensor disconnected, the fuel tank pressure sensor voltage should be less than 0.2 V if the ECM and wiring are OK.
3. Probing the ground circuit with a test light checks the circuit for high resistance which will cause a DTC P0453 to set.
4. A shorted 5 volt reference circuit will also set additional DTCs.
5. The replacement ECM must be reprogrammed.
Refer to the latest Techline procedure for ECM reprogramming.

Step 1-6:

Step 7-13:

Troubleshooting