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 provide an overview of each diagnostic category. |
DTC Descriptor
DTC P0496 : Evaporative Emissions (EVAP) System Continuous Purge Flow.Circuit Description
This DTC tests for continuous intake manifold vacuum flow to the Evaporative Emission (EVAP) System. The control module seals the EVAP system by commanding the EVAP canister purge solenoid valve Closed and the EVAP canister vent solenoid valve Closed. The control module 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 greater than a predetermined value within a predetermined time, this DTC sets.
FTP Sensor Signal Voltage | Fuel Tank Pressure |
|---|---|
High, Approximately 1.5 Volts or More | Negative Pressure/Vacuum |
Low, Approximately 1.5 Volts or Less | Positive Pressure |
Conditions for Running the DTC
| • | DTCs P0106, P0107, P0108, P0112, P0113, P0117, P0118, P0122, P0123, P0131, P0132, P0133, P0134, P0137, P0138, P0140, P0141, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0402, P0404, P0405, P0406, P0444, P0445, P0452, P0453, P0462, P0463, and P0502 are not set. |
| • | The ignition 1 voltage is between 11-16 volts. |
| • | The barometric pressure (BARO) is greater than 72 kPa. |
| • | The start-up IAT minus the startup ECT is less than 12°C (53°F). |
| • | The start-up ECT minus startup IAT is less than 50°C (122°F). |
| • | The start-up ECT and IAT is between -5 and +40°C (+23 and +104°F). |
| • | The start-up IAT is 3°C (37°F) less than the actual IAT. |
| • | Purge start time is less than 360 seconds. |
| • | Engine Run Time is greater than 1 second and less than 120 seconds. |
| • | DTC P0496 runs once an ignition cycle when the above conditions are met. |
Conditions for Setting the DTC
The FTP sensor indicates vacuum during a non-purge condition.
Action Taken When the DTC Sets
DTC P0496 is a Type A/B DTC.
Conditions for Clearing the DTC
DTC P0496 is a Type A/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. |
Reference Information
Schematic Reference
Evaporative Emissions Hose Routing Diagram
Description and Operation:
Evaporative Emission Control System Description
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Special Tools Required
| • | J 41413-300 EVAP Cap and Plug Kit |
| • | J 23738-A Hand Vacuum Pump |
Circuit/System Testing
- Ignition ON, loosen the fuel fill cap. Verify the scan tool FTP sensor parameter is 0 mmHg (0 inches H20).
- Disconnect the purge line from the EVAP purge solenoid valve and connect a J 23738-A hand vacuum pump.
- Verify the solenoid can hold 10 inches of vacuum for 30 seconds.
| ⇒ | If not at the specified value, replace the FTP sensor. |
| ⇒ | If the vacuum decreases, replace the EVAP purge solenoid valve. |
Repair Instructions
Evaporative Emission Canister Purge Solenoid Valve Replacement
Repair Verification
- Disconnect the EVAP vent line from the vent solenoid and seal it, using a suitable plug from the J 41413-300 .
- Start the engine and Increase the engine idle to 1,200-1,500 RPM.
- Verify the scan tool FTP sensor parameter is -1 to +1 in H2O.
- Clear the DTCs with a scan tool.
