P0496

DTC P0496

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* 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 System Flow During Non-Purge

Diagnostic Fault Information






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, P0112, P0113, P0116, P0117, P0118, P0121, P0122, P0123, P0128, P0442, P0443, P0446, P0449, P0452, P0453, P0502, P0503 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 start-up engine coolant temperature (ECT) is less than 35°C (95°F).
* The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
* The start-up ECT and IAT are within 8°C (14.4°F) of each other.
* The vehicle speed sensor (VSS) is less than 121 km/h (75 mph).
* DTC P0496 runs once per cold start within 17 minutes.

Conditions for Setting the DTC

* The ECM detects vacuum during a non-purge condition.
* The fuel tank vacuum is greater than 10 inches H2O for 5 seconds within 60 seconds of cold start.

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.

Circuit/System Testing

1. Start the engine.
2. Seal the EVAP system using the Purge/Seal function with a scan tool.
3. 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 after completing the diagnostic procedure. Verification Tests

Evaporative Emission Canister Purge Solenoid Valve Replacement