Buick Regal: DTC P0455
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- 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 engine control module (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 vent solenoid valve and purge solenoid valve ON, allowing
vacuum into the EVAP
system. The ECM monitors the fuel tank pressure 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
- DTCs P00C8, P00C9, P010C, P010D, P16A0, P16A1, P16A2, P160E, P160D,
P16F3, P0068,
P0101, P0102, P0103, P0111, P0112, P0113, P0114 P0116, P0117, P0118, P0122,
P0123, P0125,
P0128, P0191, P0192, P0193, P0222, P0223, P0443, P0449, P0452, P0453, P0454,
P0502, P0503,
P0601, P0604, P0606, P0722, P0723, P1104, P1682, P2100, P2101, P2102, P2103,
P2135, P2176,
P2227, P2228, P2229, P2230 are not set.
- The ignition voltage is between 11 - 32 V.
- The barometric pressure (BARO) is greater than 70 kPa.
- The fuel level is between 10 - 90%.
- The cold startup engine coolant temperature (ECT) and the startup intake
air temperature (IAT)
are within 8ºC (14ºF).
- The startup engine coolant temperature (ECT) is less than 35ºC (95ºF).
- The startup intake air temperature (IAT) is between 4 - 34ºC (39 -
93ºF).
- DTC P0455 runs once per cold start, shortly after purge is enabled
followed by vent system
performance test P0446.
Conditions for Setting the DTC
- The EVAP system is not able to achieve or maintain a calibrated level of
vacuum before a
calibrated amount of purge volume has passed through the system.
- After setting the DTC for the first time, 2 L (0.5 gal) of fuel must be
consumed before setting the
DTC for the second time.
- With a DTC P0455 detected a weak vacuum follow-up test (fuel cap
replacement test) will run
and pass if tank vacuum is greater than 2.74 kPa (11 in H2O). This test will
run for a maximum of
21 min. This test runs until it passes.
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 injected. For example, when injecting
smoke at the service
port remove the fuel fill cap, or temporarily leave the vent open, until
smoke is observed, then
close the system and continue testing. If using a fuel cap adapter at the
filler neck, use the J-
41413-VLV at the service port to allow the system to fill faster.
- To help locate intermittent leaks using the GE-41413-A move all EVAP
components while observing smoke with the GE-41413-SPT.
- Individual components can be isolated and tested using adapters in the
J-41413-300.
- When servicing the EVAP system, test pressure must not exceed 13 in H20
(0.5 PSI) as pressure
in excess of this could cause system components to perform inaccurately.
- A condition may exist where a leak in the EVAP system only exists under
a vacuum condition.
- This type of leak may be detected by using the scan tool Purge/Seal
function to create a vacuum in the EVAP system and then observe the Fuel
Tank Pressure Sensor parameter for vacuum decay.
Reference Information
Schematic Reference
Engine Controls Wiring Schematics (LTG)
Connector End View Reference
Component Connector End View Index
Powertrain Component View
Powertrain Component Views
Description and Operation
Evaporative Emission Control System Description
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Special Tools
- CH-48096 EVAP Service Access Port Tool
- GE-41413-A Evaporative Emissions System Tester
- GE-41413-SPT High Intensity White Light
- GE-41415-30 Fuel Tank Cap Adapter
- GE-41415-60 Engine Induction System Leak Test Adapter/Capless Fuel Fill
Adapter
- J-41413-300 EVAP Cap and Plug Kit
- J-41413-311 EVAP Plug (Brass Nozzle)
- J-41413-VLV EVAP Service Port Vent Fitting
For equivalent regional tools, refer to Special Tools (Diagnostic Tools) and
Special Tools (Mechanical
Tools)
Circuit/System Testing
NOTE:
- Larger volume fuel tanks and/or those with lower fuel levels may
require several minutes for the floating indicator to stabilize or
produce smoke from a leak.
- Refer to the GE-41413-A detailed instructions in Evaporative
Emission System Diagnosis.
1. Disconnect the purge tube at the quick connector on the EVAP canister side
of the purge solenoid valve and install the CH-48096.
2. Connect the GE-41413-A to the vehicle EVAP service port adapter.
3. Ignition ON, command the EVAP Purge/Seal function to Not Venting or System
Seal with a scan
tool to seal the EVAP system.
4. Verify that there is no leak in the EVAP system using the flow meter on the
GE-41413-A ,
calibrated to 0.51 mm (0.020 in).
- Apply smoke to the EVAP system at the service access port adapter with
the GE-41413-A.
- Locate the leak using the GE-41413-SPT.
- When the leak is located, repair or replace the affected component
as necessary.
- Go to next step: If no leak detected
NOTE: The steps below test for a restriction in the purge path.
5. Connect the GE-41413-A nitrogen/smoke hose to the J-41413-311 or
GE-41415-60 for capless
vehicles.
6. Disconnect the hose at the fuel cap end of the GE-41415-30 and connect to the
J-41413-311.
7. Install the GE-41415-30 or GE-41415-60 , filler neck end only, to the
vehicle.
8. Engine idling, command the Purge/Seal function to Not Venting or System Seal
with a scan tool to
seal the system.
NOTE: The scan tool will abort purge when a predetermined value is
reached. This is to prevent damage to the fuel tank.
9. Command the EVAP Purge Solenoid Valve to 10-30% with a scan tool.
10. Verify the vacuum/pressure gauge on the GE-41413-A and the scan tool Fuel
Tank Pressure
Sensor parameter both show vacuum.
- If the vacuum/pressure gauge shows vacuum but the Fuel Tank Pressure
Sensor
parameter does not show vacuum
Replace the B150 Fuel Tank Pressure Sensor.
- If both do not show vacuum
Repair the restriction in the purge path.
- Go to next step: If both show vacuum
11. Verify that the Fuel Tank Pressure Sensor parameter increases to greater
than 3.2 V, and the pressure values are similar between the scan tool Fuel Tank
Pressure Sensor and the vacuum/pressure gauge on the GE-41413-A.
- If not within the specified range
Replace the B150 Fuel Tank Pressure Sensor.
- Go to next step: If within the specified range
12. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Fuel Tank Pressure Sensor Replacement (FWD) or Fuel Tank Pressure Sensor
Replacement
(AWD)
- Control Module References for control module replacement, programming
and setup.
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diag
SEE MORE:
The exterior lamp control is on the
instrument panel to the left of the
steering column.
There are four positions.
: Turns the exterior lamps off and
deactivates the AUTO mode. Turn
to again to reactivate the
AUTO mode.
In Canada, the headlamps will
automatically reactivate when the
vehicle is
Preliminary Procedure
Electronic Brake and Traction Control Module with Brake Pressure Modulator
Valve
Replacement (2.0L LTG) or Electronic Brake and Traction Control Module with
Brake
Pressure Modulator Valve Replacement (3.6L LGX)
Brake Pressure Modulator Valve Bracket Bolt
CAUTION:
Fastene