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P0497




DTC P0497

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 P0497
- Evaporative Emission (EVAP) System No Flow During Purge

Circuit/System Description

This DTC tests for proper intake manifold vacuum flow to the evaporative emission (EVAP) system. The engine control module (ECM) opens the EVAP canister purge solenoid valve and closes the EVAP canister vent solenoid valve. The control module then 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 less than a predetermined value within a predetermined time, this DTC sets.

The diagnostic is executed, once per trip, when the engine is running with purge enabled. There is a time delay after purge is enabled before this diagnostic can start. The time delay depends on whether the FTP sensor indicates pressure or vacuum. The initial state of the vent solenoid will be closed if there is still pressure in the tank after the time delay. The initial state of the vent solenoid will be open if there is vacuum in the tank.

When the commanded purge duty cycle is above a threshold, the EVAP leak detection pump switching valve transitions from vent to not venting position to prepare to create a vacuum. The EVAP leak detection pump pressure sensor, absolute, is monitored and compared to the initial value after the EVAP leak detection pump switching valve transitions from vent to not venting position and the vent solenoid is opened. The EVAP leak detection pump pressure sensor, absolute, must have a vacuum increase within a time period to indicate purge flow and pass the DTC P0497. Otherwise, P0497 fails.

After the diagnostic reports a decision, there is a time period to allow the vacuum in the fuel tank to bleed down before completing the diagnostic. This is to prevent the fuel tank protection logic from executing.

Conditions for Running the DTC

* The purge solenoid is open.
* The vent solenoid is open.
* The EVAP leak detection pump switching valve transitions from vent to not vent, pumping, to vent.
* The EVAP leak detection pump is OFF.
* The ignition voltage is greater than 11 volts.
* The barometric pressure (BARO) is between 70-110 kPa (10-16 PSI).
* The outside air temperature is between 4-35°C (35.6-95°F).
* DTC P0497 will run once per trip with propulsion system active and engine ON.
* Engine RPM to enable between 1500-3400
* Engine RPM to re-enable between 1600-3300
* Engine vacuum to enable between 10-37 kPa (1.5-5.4 PSI)
* Engine vacuum to re-enable between 11-35 kPa (1.6-5.1 PSI)
* Engine airflow to enable between 9-34 gps
* Engine airflow to re-enable between 10-32 gps
* Purge flow to enable greater than 0.14 gps
* Purge flow to re-enable greater than 0.13 gps
* Purge DC to enable greater than 15%
* Purge DC to re-enable greater than 16%
* Requested purge flow to enable greater than 1.45%
* Delivered purge flow to greater than 1.40%
* Delivered purge flow to enable greater than 1.10%
* Engine Running
* Purge is enabled

If any of these conditions occur this test is aborted.
* Refueling request button pressed
* Device control exceeds 0.5 seconds
* Fuel tank protection active when FTP sensor is below 3.23 kPa (0.47 PSI) for 5 s.
* P0068, P0071, P0072, P0073, P0106, P0107, P0108, P0122, P0123, P0222, P0223, P0443, P0449, P0451, P0452, P0453, P0455, P0458, P0459, P0498, P0499, P0502, P0503, P0606, P0722, P0723, P16F3, P1104, P1458, P1459, P145A, P145D, P145E, P2100, P2101, P2102, P2103, P2400, P2401, P2402, P2418, P2419, P2420, P2422, P2450 are not present.

Conditions for Setting the DTC

After an initial time delay of 3 s when the FTP sensor reading is above 0.966 kPa (0.140 PSI), or after an initial time delay of 10 s when the FTP sensor reading is below 0.996 kPa (0.140 PSI) plus an EVAP leak detection pump switching valve delay time of 0.2 s, if the EVAP leak detection pump pressure sensor, gauge, indicates a vacuum change of 2 kPa (0.29 PSI) for 10 s, then a low purge flow failure has been detected and the DTC fails.

Action Taken When the DTC Sets

DTC P0497 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0497 is a Type B DTC.

Diagnostic Aids

* A loose, missing, or damaged fuel fill cap can cause this DTC to set.
* A stuck closed, blocked, or restricted EVAP canister purge solenoid valve, can cause this DTC to set.
* A blockage or restriction in the EVAP canister purge solenoid valve vacuum supply hose, EVAP canister purge solenoid valve purge pipe, EVAP canister, or vapor pipe, can cause this DTC to set.
* A temporary blockage in the EVAP canister purge solenoid valve, purge pipe or EVAP canister could cause an intermittent condition. Inspect and repair any restriction in the EVAP system.
* To help locate intermittent leaks, use the J 41413-200 - evaporative emission system tester to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT - white light. Introducing smoke in 15 s intervals will allow less pressure into the EVAP system. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.
* To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT - white light.
* Observe the Freeze Frame/Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition occurs that caused the DTC to set. This may assist in diagnosing the condition.

Reference Information
Schematic Reference

Engine Controls Schematics [1][2]Electrical Diagrams
Description and Operation

Evaporative Emission Control System Description Evaporative Emission Control System Description

Hybrid Modes of Operation Description Hybrid Modes of Operation Description
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1 A4
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
Special Tools

* EN 41413-200 - Evaporative Emissions System Tester (EEST)
* EN 41413-300 - EVAP Cap And Plug Kit
* EN 41413-SPT - High Intensity White Light
* GE 41415-30 - Fuel Tank Cap Adapter

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Special Tools (Diagnostic Tools).

Circuit/System Verification

Note: Larger volume fuel tanks and/or those with lower fuel levels may require several minutes for the floating indicator to stabilize. Refer to EN 41413-200 - Evaporative Emissions
System Tester operation manual for detailed instructions in Evaporative Emission Control System Diagnosis.

1. Connect the EN 41413-200 - nitrogen/smoke hose to the EN 41413-311 - brass cone adapter. Disconnect the hose at the fuel cap end of the GE 41415-30 - fuel tank cap adapter. Connect the EN 41413-311 - brass cone
adapter to the disconnected hose on the GE 41415-30 - fuel tank cap adapter. Install the GE 41415-30 - fuel tank cap adapter filler neck end only to the vehicle.
2. Be sure the EVAP leak detection pump switching valve is in the vent position.
3. Use the flow meter on the EN 41413-200 - EEST calibrated to 0.51 mm (0.020 in) to determine there is no leak in the EVAP system.

• If a leak is detected, use the EN 41413-200 - EEST to apply smoke to the EVAP system at the filler neck until the leak is located.

Circuit/System Testing

Note: Perform the Circuit/System Verification before proceeding with the Circuit/System Testing.

1. Ignition ON, engine running.
2. Seal the EVAP system using the EVAP Test function with a scan tool.
3. Observe the FTP sensor with a scan tool. The FTP Sensor parameter should be more than 2 volts within 60 seconds.

• If the FTP Sensor parameter is less than the specified range, repair the blocked purge path or replace the EVAP canister purge solenoid valve.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

Evaporative Emission Canister Purge Solenoid Valve Replacement Service and Repair

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