20 Most Recent 2006 GMC Sierra - Page 4 Questions & Answers

You have triggered the anti theft security system. http://vatspasslockpasskeysecurityhelp.yolasite.com/

Since a recode will fix the problem for a couple of months, I would guess it is how you are carrying or storing your key instead of something in the vehicle. Are you putting them close to your cell phone or other electronic device? If so try to change your habit and store them away from anything electronic (including your alarm clock).

Most common, internal problem within instrument cluster. R/R cluster and sublet to speedo shop for repair.

check grounds,check ignition switch,they do wear out

Just to confirm, you don't have an electrical 4WD selector; you have to move a shifter on the floor of our cab? If that's the case, I'd suspect that you have a linkage misalignment or malfunction that doesn't allow the 4WD selector to completely return to the 2WD position. Putting the truck into reverse and back to drive probably causes a jolt to the 4WD linkage which disengages the transfer case from the driveline. Check for slack or binding in the transfer case shift level linkage (clean and lube the linkage won't hurt).

The "check engine" light is an indicator for a system that monitors many electronic functions in the system, also called the "malfunction indicator lamp" (MIL). It can come on for any of hundreds of different causes from any of the systems that the computer monitors. Some are very important and can lead to further component or engine damage and some are emissions related not as serious but still a problem and need to be repaired. Your first step is to have the computer scanned to retrieve the trouble codes that were set when the check engine light came on. Those codes will give you specific information about what the computer saw and will get you pointed in the right direction to find your problem. With a 1996 or newer and some 95 cars and you have an AutoZone or Advanced auto parts in your area, they will read them for free. Once you have these code numbers, we can be a lot more specific about what your problem may be.

blower module has open circuit on top two speeds,module needs replaced.

p0449 is an evaporative emission code that indicates a problem with the canister vent solenoid.. without being able to scan and check all of the system I would recomend replacing the vent solenoid. I believe their was a GM TSB on that part and it has been modified.
please respond with fix details

Here's a little more info on the situation

http://www.obd-codes.com/p0455