DTC Advanced Diagnostics: P0499
DTC P0499:Evaporative Emission (EVAP) Canister Vent Shut Valve Circuit High Voltage

General Description

The evaporative emission (EVAP) canister vent shut valve is attached to the EVAP canister to control the venting of the EVAP canister to atmosphere. The EVAP canister vent shut valve is open (open to atmosphere) when the VSV signal is OFF. If the return signal is "ON" when the powertrain control module (PCM) outputs the "OFF" signal to the EVAP canister vent shut valve, the PCM detects a malfunction and stores a DTC.

Monitor Execution, Sequence, Duration, DTC Type
Execution
Continuous
Sequence
None
Duration
5 seconds or more
DTC Type
Two drive cycles, MIL on

Enable Conditions
Condition
Minimum
Maximum
12 volt battery voltage [BATTERY]
10.0 V
–
State of the engine
Running
[ ]: HDS Parameter

Malfunction Threshold
The return signal is "ON" for at least 5 seconds when the PCM outputs the "OFF" signal to the EVAP canister vent shut valve.

Possible Cause
NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
EVAP canister vent shut valve VSV line short to power
EVAP canister vent shut valve failure
PCM internal circuit failure

Confirmation Procedure
Operating Condition
Start the engine.

With the HDS
Select the EVAP TEST in the INSPECTION MENU, and do the EVAP CVS ON in the SINGLE SOLENOID with the HDS.

Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected during the first drive cycle, a Pending DTC is stored in the PCM memory. If the malfunction returns in the next (second) drive cycle, the MIL comes on and a Confirmed DTC and the freeze data are stored.

Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, and the freeze data can be cleared with the scan tool Clear command or by disconnecting the 12 volt battery.