My 2004 that i just bought keeps setting a code of,, P0492. aND THE DEALER HAS RESET THE LIGHT TWICE, BUT WE ALL KNOW THIS ISNT A FIX.--- cOULD ANYONE SHARE INFO TO ME ON WHAT THE PROBLEM MAY BE ??? - AS im a new vett owner and unfamilar with the veh

 

Try using the SEARCH function up top to search for the code, and you do NOT need a dealer to reset, you can do it from the Driver Information Center (DIC) on the dash.

 

That code is for the secondary air injection (AIR) system. It shouldn't cause you any problem with the operation of the vehicle and commonly is caused by sticking bypass valves. You should look into getting a service manual on CD. They can be bought pretty cheaply ($30.00 or less) or there are sites you can do a free download.

To pull your codes:

To enter the Diagnostic Display function perform the following steps in order:

1. Turn ON the ignition switch, engine OFF.
2. Press the RESET button to acknowledge any warning messages present.
3. Press the OPTIONS button on the Driver Information Center (DIC) and hold.
4. While holding the OPTIONS button press the FUEL button 4 times within a 10 second period.
5. System will first enter automatic display mode followed by the manual display mode.

The automatic display feature allow you to read each module DTC display function in an automatic display sequence. Each system module DTC will be displayed for 3 seconds followed by a 1 second pause before the next DTC is displayed in an automatic sequence. If no DTC information is sent to the IPC from the system currently displayed on the IPC, the IPC will display NO CODES for that system. At any time during the automatic display function, the manual display feature can be activated by pressing any button on the DIC except the E/M 5 button. The E/M 5 button is used to completely exit the DIAGNOSTICS mode at any time. If there is a communications problem between any system, the IPC will display NO COMM when the IPC is trying to communicate with that system. When all DTCs have been displayed for all systems, the IPC will display NO MORE CODES for 2 seconds then will enter the manual display mode, waiting for manual mode operation.

The manual display feature allows you to manually select each module DTC display function. The manual mode will automatically be entered after the automatic DTC display sequence is complete, or can be entered at any time during the automatic mode by pressing any button on the DIC except the E/M 5 (E/M 5 button is used to exit the DIAGNOSTIC mode at any time). When the manual mode is selected, the IPC will display the MANUAL DIAGNOSTICS mode message for 2 seconds, or until any button on the DIC except the E/M 5 is pressed. After the MANUAL DIAGNOSTICS mode message is displayed, the IPC will display the first system abbreviation and quantity of codes stored for that system, then the IPC will wait for further instructions. The buttons on the DIC provide the following functions when operating the on-board diagnostic feature in the manual mode:

DIC Button Function

FUEL 1 Previous DTC
GAGES 2 Next DTC
TRIP 3 Previous System
OPTIONS 4 Next System
E/M 5 Exit Diagnostics
RESET Clear DTCs

 

So where are or is the bypass valves ???

 

Here you go. Hope this helps you.
Air check valve bank 1

Air check valve bank 2

 

yea ,, called dealer today and they claim that they didnt just turn light off,,,? - but that they downloaded ?? new software ? [ecm] ?and are talking with gm ? and now that its back on they are saying i have to wait till monday to see when parts will be avalible from gm.- And they say intake has to come off, to replace part,or parts. -- Any idea guys what part they may be refering too under intake, with my P0492 CODE

 

Air check valve bank 2, It's behind the intake.