P0453

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The fuel tank pressure sensor is used in order to detect a vacuum decay or an excessive vacuum during the EVAP diagnostic routine. The sensor responds to the changes in the fuel tank pressure or vacuum. The signal voltage to the Powertrain Control Module (PCM) varies from a minimum of about 0.2 voltswith pressure in the fuel tank to more than 4.0 volts with a high vacuum in the fuel tank.

CONDITIONS FOR RUNNING THE DTC
The engine is running.

CONDITIONS FOR SETTING THE DTC
The fuel tank pressure sensor voltage is more than 4.9 volts for more than 25 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The Malfunction Indicator Lamp (MIL) will illuminate.
^ The PCM will record the operating conditions at the time that the diagnostic fails. The Freeze Frame and Failure Records buffers will store this information.
^ A history DTC stores.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The 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 to clear the DTCs.

DIAGNOSTIC AIDS
Check for the following conditions:
^ Inspect the PCM harness electrical connectors for the following conditions:
- Any incorrect mating
- Any broken locks
- Any incorrectly formed terminals
- Any damaged terminals
^ Inspect the wiring harness for damage. If the harness appears to be OK, observe the Fuel Tank Pressure display on the scan tool while moving the electrical connectors and the wiring harnesses related to the sensor. A change in the display will indicate the location of the malfunction.

TEST DESCRIPTION
Numbers below refer to the step numbers on the diagnostic table.
2. This step will determine if DTC P0453 is the result of a hard malfunction or an intermittent condition.
3. This step simulates the conditions for DTC P0452. If the PCM recognizes the change, that indicates that the following items are OK:
^ The PCM
^ The 5.0 V reference circuit for the fuel tank pressure sensor
^ The signal circuit for the fuel tank pressure sensor
5. This step looks for an open in the sensor ground circuit.
6. When the sensor signal circuit is shorted to battery voltage, the TP will be displayed above 0 percent at all times and the A/C High Side will be displayed high. The vehicle will also remain in Open Loop.

IMPORTANT: The PCM uses a single 5.0 volt power supply to supply power to all the engine control components. If one component shorts the 5.0 volt reference circuit to ground or battery voltage, the other 5.0 volt reference circuits will also have a low or high voltage.

8. Disconnect all the sensors that use a 5.0 volt reference one at a time while monitoring the short on the 5.0 volt reference circuit. Repair any circuit or replace any sensor that may have caused the short on the 5.0 volt reference circuit.
10. The replacement PCM must be programmed and the Crankshaft Position System Variation Learn procedure must be performed.