Chevrolet Trax: 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 table listed below 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 P0068, P00C8, P00C9, P00CA, P0090, P0091, P0092, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0122, P0123, P0125, P0128, P0191, P0192, P0193, P0222, P0223, P0601, P0604, P0606, P0697, P06A3, P06DB, P06DE, P0A1D, P1104, P127A, P127C, P127D, P15F2, P160D, P160E, P1682, P16A0, P16A1, P16A2, P16F3, P0443, P0449, P0452, P0453, P0454, P0502, P0503, P0722, P0723, P2100, P2101, P2102, P2103, P2122, P2123, P2127, P2128, P2135, P2138, P215B, P2176, P228C, P228D, U0073, U0074, U0293, U1817, are not set.
• The ignition voltage is between 11-32 V.
• The engine OFF time is greater than 48 min,
• 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 4-34ºC (39-93ºF).
• 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.
• This test will run with the purge valve closed and the vent valve closed.

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:

• Improper installation
• Damaged
• Temporary blockage
• Valve or system tubing restriction

Reference Information

Schematic Reference

Engine Controls Schematics (Encore) , Engine Controls Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

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 (LUV) , Powertrain Diagnostic Trouble Code (DTC) Type Definitions (2H0)

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.

• If the DTC sets

Refer to Circuit/System Testing

• If the DTC does not set

3. All OK

Circuit/System Testing

NOTE:

• Vehicle and service department temperature and fuel level (vapor pressure) can affect the fuel tank pressure sensor parameter. Ensure the vehicle temperature has stabilized to service department temperature to ensure greatest accuracy.
• Be sure the EVAP Purge Solenoid Valve command is 0% or this test will not work.

1. Ignition ON.
2. Command the EVAP Purge/Seal function to System Seal or Not Venting with a scan tool.
3. Engine Running.
4. Verify the Fuel Tank Pressure Sensor parameter is less than 1.9 V for greater than 90 s.

• If greater than 1.9 V

Replace the Q12 Evaporative Emission Purge Solenoid Valve

• If less than 1.9 V

5. All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Evaporative Emission Canister Purge Solenoid Valve Replacement

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