Cadillac CTS Trouble Code P0496
Cadillac Trouble Code P0496 indicates an EVAP Flow During Non-Purge Condition. This means your Cadillac CTS's engine control module (ECM) checked and found an undesired intake vacuum flow in the EVAP system while it was running a test for a P0496 trouble code.
The way the ECM tested for this condition was it sealed the EVAP system by commanding the EVAP canister PURGE solenoid valve OFF and the EVAP canister VENT solenoid valve ON. The ECM then monitored the fuel tank pressure (FTP) sensor and determined a vacuum being drawn into the EVAP system. The vacuum in your Cadillac's EVAP system was determined to be greater than the preset value within the ECM, and the ECM triggered on the Malfunction Indicator Lamp (MIL).
A faulty gas cap should not trigger a DTC P0496. Potential faults your Cadillac CTS might be experiencing which could have caused a P0496 EVAP trouble code include:
- faulty purge or vent solenoid/valve (common fault)
- plugged EVAP canister
- poor electrical connection to the any of the EVAP sensors or solenoids
- faulty canister purge valve
- blocked vapor canister
The most common fix for DTC P0496 is replacing the purge solenoid valve.
In terms of the MIL not having turned on in the 50 miles or so that you've driven you should keep in mind the P0496 DTC test only runs under these specific parameters:
- Your Cadillac ignition voltage is between 10-18 volts .
- The barometric pressure (BARO) is more than 75 kPa .
- Your Cadillac CTS fuel tank level is between 15-85 percent .
- The engine coolant temperature (ECT) is between 39-86°F .
- The intake air temperature (IAT) is between 39-86°F .
- The start up ECT and IAT are within 16°F of each other.
- Your Cadillac's speed sensor (VSS) indicates less than 75 mph .
DTC P0496 runs once per cold start when the above conditions are met, meaning it may take more than a one time 50 mile drive to check for P0496 to reappear.
Failure for illuminated Malfunction Indicator Lamp (MIL) is a functional smog check failure.
