锟斤拷If less than the specified range, test the signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the
ECM.
6. If all circuits test normal, test or replace the FTP sensor.
Repair Instructions
* For DTC P0452 or P0453, always perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic
procedure
* For DTC P0451 or P0454, clear DTCs with a scan tool
* Control Module References (See: Testing and Inspection/Programming and Relearning) for ECM replacement, setup and programming
P0455
DTC P0455
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic System
Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Strategy Based Diagnosis) for an
overview of the diagnostic approach.
* Diagnostic Procedure Instructions (See: Testing and Inspection/Initial Inspection and Diagnostic Overview/Diagnostic Procedure
Instructions)provides an overview of each diagnostic category.
DTC Descriptor
DTC P0455
- Evaporative Emission (EVAP) System Large Leak Detected
Circuit/System Description
The ECM tests the Evaporative Emission (EVAP) System for a large leak or restrictions to the purge path in the EVAP system. When the enabling
criteria has been met the ECM commands the EVAP canister vent solenoid valve ON and the EVAP canister purge solenoid valve ON, allowing
vacuum into the EVAP system. The ECM monitors the fuel tank pressure (FTP) sensor voltage to verify that the system is able to reach a
predetermined level of vacuum within a set amount of time.
Conditions for Running the DTC
* Before the ECM can report DTC P0455 failed, DTC P0496 must run and pass.
* DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0449, P0451,
P0452, P0453, P0454, P0464, P0496, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128,
P2135, P2138 are not set.
* The ignition voltage is between 11-18 volts.
* The barometric pressure (BARO) is more than 74 kPa.
* The fuel level is between 15-85 percent.
* The engine coolant temperature (ECT) is less than 35锟斤拷C (95锟斤拷F).
* The intake air temperature (IAT) is between 4-30锟斤拷C (39-86锟斤拷F).
* DTC P0455 runs once per cold start when the above conditions are met.
Conditions for Setting the DTC
The EVAP system is not able to achieve or maintain a calibrated level of vacuum within a set amount of time.
Action Taken When the DTC Sets
DTC P0455 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0455 is a Type B DTC.
Diagnostic Aids
* Inspect for a loose, missing, damaged, or incorrect fuel fill cap.
* Inspect for a damaged fuel filler neck seal surface.
* A blockage or restriction in the EVAP purge solenoid valve, purge pipe, EVAP canister, or vapor pipe, can cause this DTC to set.
* The EVAP system can be filled with smoke more quickly and completely by opening the system opposite the end where the smoke is
