my 2007.5 lmm with 6000 miles,just went into limp home mode.our local chev dealer refused to look at it because its a gmc and i didnt buy from him.went to the nearest gmc place-20 miles away.didnt buy it there either but they were super helpful.got me right in said it needed a new program downloaded.it showed too much air past the egr.they said that should fix it but if not they would put me in a rental car. well it did fix it.they even washed my truck before giving it back. apparently this is a common problem on the lmm they have seen several and gm is trying hard to rectify without bad press. oh ,my truck is bone stock so far except for 17x9 wheels that the dealer put on.

I just don't get this type of bs from the dealers. I called GM when it happened to me. I was pissed! Gm agreed with me that it should never happen and called the dealer while I was on hold. She went thru the same info as I did and when the service writer asked if she bought the truck there, She stated NO! He stated they would NOT do any warranty work on her truck! GOTCHA! She then informed them of who she was (GM CORP REP) and stated that she needed to talk with the owner of the dealership.

Long story short is this dealer is now under the eyes of GM. They don't want to hear customers not recieving warranty work. This leads to bad press, loss of sales etc. I was then told by this same lady to try and find another dealership to do my warranty work. She would do this if it were her truck! That says a lot to me. She also stated that this will be forwarded up the chain as GM is trying to crackdown on this type of problem. Remember the GM logo means the warranty work should be able to be handled anywhere in the WORLD not just where you bought it!

my 2007.5 lmm with 6000 miles,just went into limp home mode.our local chev dealer refused to look at it because its a gmc and i didnt buy from him.went to the nearest gmc place-20 miles away.didnt buy it there either but they were super helpful.got me right in said it needed a new program downloaded.it showed too much air past the egr.they said that should fix it but if not they would put me in a rental car. well it did fix it.they even washed my truck before giving it back. apparently this is a common problem on the lmm they have seen several and gm is trying hard to rectify without bad press. oh ,my truck is bone stock so far except for 17x9 wheels that the dealer put on.

my 2007.5 lmm with 6000 miles,just went into limp home mode.our local chev dealer refused to look at it because its a gmc and i didnt buy from him.went to the nearest gmc place-20 miles away.didnt buy it there either but they were super helpful.got me right in said it needed a new program downloaded.it showed too much air past the egr.they said that should fix it but if not they would put me in a rental car. well it did fix it.they even washed my truck before giving it back. apparently this is a common problem on the lmm they have seen several and gm is trying hard to rectify without bad press. oh ,my truck is bone stock so far except for 17x9 wheels that the dealer put on.
Hope that fixed it for good .Would like to know if it happens again. Four times on my LMM.

im pretty sure gm has told dealers not to do cross-line warranty work unless it is an emergency

had the same code 401-402 and 2456 something took it back to the dealer said it needed update lasted 2 weeks now its at the dealer 2 weeks needs exhaust filter egr and some lines any thoughts to this

had the same code 401-402 and 2456 something took it back to the dealer said it needed update lasted 2 weeks now its at the dealer 2 weeks needs exhaust filter egr and some lines any thoughts to this
Good luck bud. Its all the emissions on these new trucks. GM is desperately looking to resolve the issues with these new trucks. This equals numerous new down loads from your GM dealer.With the diverse driving conditions out there, there is no way GM, Ford, Or Dodge could do enough testing to have a failsafe system. Thats where you come in, the general public. Give it to the people and they will test it for you. In the mean time we,GM, will try to stay ahead of the game and try to not take to much bad press. Or maybe the good will out weigh the bad.

Good luck bud. Its all the emissions on these new trucks. GM is desperately looking to resolve the issues with these new trucks. This equals numerous new down loads from your GM dealer.With the diverse driving conditions out there, there is no way GM, Ford, Or Dodge could do enough testing to have a failsafe system. Thats where you come in, the general public. Give it to the people and they will test it for you. In the mean time we,GM, will try to stay ahead of the game and try to not take to much bad press. Or maybe the good will out weigh the bad.

Sounds like Microsoft.:eek: Maybe Bill Gates runs GM too.:D

Sounds like Microsoft.:eek: Maybe Bill Gates runs GM too.:D
The window sticker should read under the standard equipment. "Bill Gates Trim"

They have told GM dealerships NOT to do crossline warranty unless safety issue or not driveable. NO GM dealership should ever REFUSE working a vehicle that has been bought somewhere else if same franchise. GM will have thier but if they catch them. They can however "work on your customers 1st". Which I still do not think is right.

I am researching the P0402 code today. I will update ya'll on my findings.


Complete the current SI diagnostics for any trouble code or symptom found.

Completion of diagnostics for P0402 is imperative. Air Charge Cooler leaks, intake ductwork leaks, air box/air filter or modifications, EGR gasket leaks, or excessive leaks anywhere in the engine intake system may induce P0402 to set.

If diagnostics are inconclusive there is a new calibration released for P0402.

Install the updated calibration for P0402 and evaluate repairs.

Note: When completing SI diagnostics for full system air charge cooler tests remember these important facts:

The engine will not hold pressure if the gage valve is turned OFF.
An air leak hissing sound at the EGR valve vent port is normal.
An air leak that appears as small bubbles or foaming is normal.
Intake Air Heater gaskets that show a small leak or foaming is normal.

the only bad press is the dang dpf other then that the truck is awesome and with a missing dpf its even that much better

We buys GMCs but take all our GM vehicles to one guy at a Chevy dealer. Never had any problem doing anything for us since they all fall under the GM umbrella.

We buys GMCs but take all our GM vehicles to one guy at a Chevy dealer. Never had any problem doing anything for us since they all fall under the GM umbrella.
It's who you know,not who you don't.

It's who you know,not who you don't.


YEP.. and if your GM rep is helpful or an azz.. :D

we have a GM rep that is a total butt. Our old rep would help us. this one is too much of a "by the book" person...