P0496
DTC P0496
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructionsprovides an overview of each diagnostic category.
DTC Descriptor
DTC P0496
- Evaporative Emission 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 canister purge solenoid valve OFF and the EVAP canister 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 canister purge and vent solenoid valves.
Conditions for Running the DTC
* DTCs P0106, P0107, P0108, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0451, P0452, P0453, P0454, P0464, P0608, P0609, P0641, P0651, P1516, P2101, P2119, P2120, P2122, P2123, P2125, P2127, P2128, P2135, P2138 are not set.
* The ignition voltage is between 11-32 volts.
* The barometric pressure (BARO) is more than 70 kPa.
* The fuel level is between 10-90 percent.
* The engine coolant temperature (ECT) is less than 35°C (95°F).
* The intake air temperature (IAT) is between 4-30°C (39-86°F).
* DTC P0496 runs once per cold start when the above conditions are met for up to 16 min.
Conditions for Setting the DTC
The ECM detects greater than 10 inch H2O (2.49 kPa) vacuum for 5 seconds 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
* Observe the freeze frame/failure records vehicle mileage since the diagnostic test last failed may help determine how often the condition occurs that caused the DTC to set. This may assist in diagnosing the condition.
* The EVAP system tests run when engine is first started and meets The conditions for running the DTC. An intermittent condition could be caused by an improperly installed or damaged EVAP canister purge solenoid valve , or by a temporary blockage or restriction in the EVAP canister purge solenoid valve or the vent side of the EVAP system.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Evaporative Emission Control System Description Evaporative Emission Control System Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Programming and Relearningfor scan tool information
Circuit/System Verification
1. Ignition ON, engine OFF, observe the Fuel Tank Pressure sensor parameter with a scan tool. The reading should not display negative inches of H2O.
• If not the specified value, remove the gas cap. If vacuum is gone inspect and repair any restriction or blockage in the vent side of the EVAP system.
2. Reinstall the gas cap then 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 Fuel Tank Pressure Sensor parameter should be less than 1.7 volts after 90 seconds.
• If the Fuel Tank Pressure Sensor parameter is greater than the specified range, replace the EVAP canister purge solenoid valve.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Evaporative Emission Canister Purge Solenoid Valve Replacement Service and Repair