For 1990-2009 cars

### 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 System Flow During Non-Purge

### Diagnostic Fault Information

Control Module Command | EVAP Canister Purge Solenoid Valve | EVAP Canister Vent Solenoid Valve
--- | --- | ---
ON | Open | Closed
OFF | Closed | Open

### 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 preceding 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 P000A, P000B, P0010, P0013, P0016. P0017, P0030, P0031, P0032, P0068, P0072, P0073, P0074, P009A, P0102, P0103, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0121, P0121, P0122, P0123, P0131, P0132, P0133, P0134, P0135, P0171, P0172, P0201, P0202, P0203, P0204, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0301, P0302, P0303, P0304, P0335, P0336, P0340, P0341, P0365, P0366, P0436, P0442, P0443, P0446, P0451, P0452, P0453, P0454, P0455, P0456, P0458, P0459, P0496, P0498, P0499, P0501, P0506, P0507, P0562, P0563, P0605, P061A, P061B, P061C, P0642, P0643, P1101, P2088, P2089, P2090, P2091, P2100, P2101, P2119, P2176, P2227, P2228, P2229, P2297, P2301, P2304, P2307, P2310, P2610, U0002, and U0073 are not set.

• | The Ignition is ON.

• | The barometric pressure (BARO) is more than 75 kPa.

• | The engine coolant temperature (ECT) is less than 110°C (230°F).

• | The engine has been running between 1-10 minutes.

• | The engine is idling.

• | The fuel level is between 6-40 liters (2-10 gallons).

• | The fuel tank pressure (FTP) is between -3 and +1 kPa (-12 and +4 in H2O).

• | The vehicle speed is 0 kph (0 mph).

• | The intake air temperature (IAT) is between -8 -70°C (17-158°F).

• | The battery voltage is more than 10 volts.

• | The engine is operating in Closed Loop fuel control.

### Conditions for Setting the DTC

The ECM detects vacuum 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.

### Reference Information

#### Schematic Reference

• | Engine Controls Schematics

• | Evaporative Emissions Hose Routing Diagram

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Troubleshooting with a Test Lamp

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

#### Special Tools

J 41413-300 EVAP Cap and Plug Kit

### Circuit/System Testing

1. Disconnect the EVAP vent pipe from the EVAP canister vent solenoid valve.
2. Seal the EVAP vent pipe using a plug from the J 41413-300 .
3. Turn ON the ignition.
4. Command the EVAP canister purge solenoid valve to 0 percent with a scan tool.
5. Start the engine.
6. 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.

Evaporative Emission Canister Purge Solenoid Valve Replacement