Buick Regal: DTC P0496
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 P0496
Evaporative Emission (EVAP) System Flow During Non-Purge
Circuit/System Description
This DTC tests for undesired intake manifold vacuum flow to the evaporative
emission (EVAP) system.
The engine control module (ECM) seals the EVAP system by commanding the EVAP
purge solenoid
valve OFF and the vent solenoid valve ON. The ECM monitors the fuel tank
pressure (FTP) sensor to
determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP
system is more than
a predetermined value within a predetermined time, this DTC sets.
The following table illustrates the relationship between the ON and OFF states,
and the Open or Closed
states of the EVAP purge and vent solenoid valves.
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 engine OFF time is greater than 8 h,
- The barometric pressure (BARO) is greater than 70 kPa.
- The fuel level is between 10 - 90 %.
- The startup engine coolant temperature (ECT) is less than 35ºC (95ºF).
- The startup intake air temperature (IAT) is between 4 - 30ºC (39 -
86ºF).
- DTC P0496 runs once per cold start, for up to 17 min, when the above
conditions are met.
Conditions for Setting the DTC
The ECM detects more than 10 in H2O vacuum for 5 s during a non-purge
condition.
Action Taken When the DTC Sets
DTC P0496 is a Type B DTC.
Conditions for Clearing the MIL/DTC
DTC P0496 is a Type B DTC.
Diagnostic Aids
An intermittent condition could be caused by an improperly installed or
damaged EVAP purge solenoid
valve or by a temporary blockage or restriction in the EVAP purge solenoid
valve.
Reference Information
Schematic Reference
Engine Controls Wiring Schematics (LTG)
Connector End View Reference
Component Connector End View Index
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
Circuit/System Verification
1. Operate the vehicle within the conditions for running the DTC. You may
also operate the vehicle
within the conditions that you observed from the freeze frame/failure records
data.
2. Verify the DTC does not set.
Refer to Circuit/System Testing
- Go to next step: If the DTC does not set
3. All OK.
Circuit/System Testing
1. Ignition ON, engine OFF.
2. Seal the EVAP system using the Purge/Seal function with a scan tool.
3. Start the engine.
4. Observe the FTP sensor with a scan tool. The FTP sensor parameter should be
less than 1.7 V
after 90 s.
- If not within specifications
Replace the Q12 Evaporative Emission Purge Solenoid Valve
- Go to next step: If within Specifications
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic
procedure.
Evaporative Emission Canister Purge Solenoid Valve Replacement.
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:
Special Tools
CH-44284-2 Fuel Flapper Door Holder
EN-41413-VLV EVAP Service Port Vent Fitting
GE-41415-60 Engine Induction System Leak Test Adapter/Capless Fuel Fill
Adapter
Operating Instructions for the Evaporative Emission System Tester
Vehicle Setup
WARNING: Refer to Fuel and Evaporative
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 Descriptors
D