P0496
DTC P0496 (LUW)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions 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 continuous 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 Closed and the EVAP canister vent solenoid valve Closed. 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 greater than a predetermined value within a predetermined time, this DTC sets.
Conditions for Running the DTC
* DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0128, P0222, P0223, P0443, P0449, P0452, P0453, P0454, P0502, P0503, P0606, P0697, P06A3, P16F3, P2101, P2122, P2123, P2127, P2128, P2135 and P2138 are not set.
* The system voltage is between 11-32 V.
* The barometric pressure (BARO) is greater than 70 kPa (10.15 PSI).
* The fuel level is between 10-90%.
* The start-up engine coolant temperature (ECT) is less than 36°C (96.8°F).
* The start-up intake air temperature (IAT) is between 4-30°C (39-86°F).
* The ignition is OFF for greater than 8 h.
* The EVAP canister purge and EVAP vent valves are closed.
* The DTC runs once per cold start within 17 minutes of start-up when the above conditions are met.
Conditions for Setting the DTC
The fuel tank pressure sensor indicates vacuum during a non-purge condition.
Action Taken When the DTC Sets
DTC P0496 is a Type B DTC.
Conditions for Clearing the DTC
DTC P0496 is a Type B DTC.
Diagnostic Aids
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.
Reference Information
Schematic Reference
Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Evaporative Emission Control System Description Description and Operation
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Engine idling, observe the scan tool Fuel Tank Pressure Sensor parameter with a scan tool. The reading should display 0 kPa (0 PSI).
2. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
Circuit/System Testing
1. Ignition ON, engine OFF, observe the scan tool Fuel Tank Pressure Sensor parameter. The reading should display 0 kPa (0 PSI).
• If not the specified value, replace the B150 Fuel Tank Pressure Sensor.
Note: Additional DTCs will set when disconnecting components.
2. Ignition OFF, disconnect the harness connector at the Q12 Evaporative Emission Purge Solenoid Valve.
Note: Depending on ambient air temperature, and fuel tank level, the fuel tank pressure may increase as the engine idles and the fuel warms up.
3. Engine idling, command the EVAP Vent Solenoid ON with a scan tool. Verify the Fuel Tank Pressure Sensor parameter display equal to, or greater than 0 kPa (0 PSI).
• If less than the specified value, replace the Q12 Evaporative Emission Purge Solenoid Valve.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
Evaporative Emission Canister Purge Solenoid Valve Replacement Service and Repair