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 00: 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 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 solenoid and EVAP canister vent solenoid valves.

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

### Conditions for Running the DTC

• | DTCs P000A 00, P000B 00, P0010 00, P001 003, P0016 00, P0017 00, P0030 00, P003 001, P0032 00, P0111 00, P0112 00, P0113 00, P0114 00, P0116 00, P0117 00, P0118 00, P0119 00, P0121 00, P0122 00, P0123 00, P0131 00, P0132 00, P0133 00, P0134 00, P0135 00, P0171 00, P0172 00, P0201 00, P0202 00, P0203 00, P0204 00, P0261 00, P0262 00, P0264 00, P0265 00, P0267 00, P0268 00, P0270 00, P0271 00, P0301 00, P0302 00, P0303 00, P0304 00, P0335 00, P0336 00, P0340 00, P0341 00, P0365 00, P0366 00, P0442 00, P0443 00, P0446 00, P0451 00, P0452 00, P0453 00, P0454 00, P0455 00, P0456 00, P0458 00, P0459 00, P0496 00, P0498 00, P0499 00, P0501 00, P0506 00, P0507 00, P0562 00, P0563 00, P061A 00, P0642 00, P0643 00, P2088 00, P2089 00, P2090 00, P2091 00, P2100 00, P2101 00, P2119 00, P2176 00, P2297 00, P2301 00, P2304 00, P2307 00, P2310 00, P2610 00, and U0073 00 are not set.

• | The ignition voltage is between 10-18 V.

• | The barometric pressure (BARO) is more than 75 kPa (11 PSI).

• | The fuel level is between 15-85%.

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

• | The intake air temperature (IAT) is between 4°C -30°C (39°F-86°F).

• | The start-up ECT and IAT are within 9°C (16°F) of each other.

• | The vehicle speed sensor (VSS) is less than 121 km/h (75 mph).

• | The fuel tank pressure sensor is less than -0.6 kPa (-4.3 PSI) at ignition ON.

• | DTC P0496 00 runs once per cold start for 96 s.

### Conditions for Setting the DTC

The engine control module detects vacuum during a non-purge condition.

### Action Taken When the DTC Sets

DTC P0496 00 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0496 00 is a Type B DTC.

### Reference Information

#### Schematic Reference

• | Engine Controls Schematics

• | LINK (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

EN-41413-300 EVAP Cap and Plug Kit

For equivalent regional tools, refer to Special Tools.

### Circuit/System Testing

1. Disconnect the EVAP vent pipe from the Q13 Evaporative Emission (EVAP) Canister Vent Solenoid Valve.
2. Seal the EVAP vent pipe using a plug from the EN-41413-300 EVAP Cap and Plug Kit .
3. Observe the B150 Fuel Tank Pressure (FTP) Sensor with a scan tool. The fuel tank pressure sensor parameter should be less than 1.7 V.

⇒ | If the fuel tank pressure sensor parameter is greater than the specified range, replace the Q12 Evaporative Emission (EVAP) Canister Purge Solenoid Valve.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | LINK (Evaporative Emission Canister Purge Solenoid Valve Replacement)

• | LINK (Fuel Tank Pressure Sensor Replacement)