| Table 1: | P0496 Evaporative Emission (EVAP) System Flow During Non-Purge |
System Description
This diagnostic monitors the evaporative emission (EVAP) system for the correct operation of the purge solenoid. The control module seals the EVAP system by commanding the EVAP canister purge valve Closed and the EVAP canister vent valve Closed. The control module monitors the fuel tank pressure (FTP) sensor in order 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 and vent valves.
Control Module Command | EVAP Canister Purge Valve | EVAP Canister Vent Valve |
|---|---|---|
ON | Open | Closed |
OFF | Closed | Open |
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0496 Evaporative Emission (EVAP) System Flow During Non-Purge
Conditions for Running the DTC
| • | DTCs P0107, P0108, P0452, P0453, P0496, P0498, P0499, P1128, P1129, P2227, P2228, and P2229 are not set. |
| • | The battery voltage is more than 10 volts. |
| • | The start-up engine coolant temperature (ECT) is between 7-35°C (20-95°F). |
| • | The start-up intake air temperature (IAT) is between 7-35°C (20-95°F). |
| • | The difference between the initial intake air temperature (IAT) and the initial engine coolant temperature (ECT) is between 6-10°C (11-18°F). |
| • | The engine is idling. |
| • | The engine is in closed loop. |
| • | DTC P0496 runs once per drive cycle when the above conditions are met. |
Conditions for Setting the DTC
The control module detects vacuum during a non-purge condition.
Action Taken When the DTC Sets
| • | The control module will illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test ran and failed. |
| • | The control module will store conditions which were present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The control module will turn OFF the MIL during the third consecutive trip in which the diagnostic ran and passed. |
| • | A history DTC clears after 40 consecutive warm-up cycles without a malfunction. |
| • | Use the scan tool in order to clear the DTC. |
Diagnostic Aids
An intermittent condition could be caused by an improperly installed or damaged EVAP canister purge valve or a temporary blockage in the EVAP canister purge valve.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Evaporative Emissions Hose Routing Diagram | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 | Are DTCs P0452, or P0453 also set? | -- | Go to Step 3 | |
Does the scan tool indicate FTP within the specified range? | -0.5 to +0.5 in H2O | Go to Step 4 | Go to DTC P0452 | |
4 |
Does the gage indicate an increase in vacuum? | -- | Go to Step 5 | Go to Diagnostic Aids |
5 | Replace the EVAP canister purge valve. Refer to Evaporative Emission Canister Purge Solenoid Valve Replacement . Did you complete the replacement? | -- | Go to Step 6 | -- |
6 |
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Steps 7 |
7 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
