Flash ecm for 20" wheels?

[gmcgrands]

I recently bought a 05 Sierra Denali and have now ordered the GM 20" wheel and tire package. I mentioned I had heard the ECM would have to be reflashed, and they looked at me with that dumb look. Can you tell me were I could find information on this? Is there a service bulliten or something? Is there any other requirments?

 

Thanks Mark

[GM-Tech]

Yes, the PCM has to be reflashed to maintain speedometer accuracy. You can refer them to this TSB: 03-03-10-006C - Sales doesn't know squat about this stuff. They only know how to sell it. Service should know though.

 

They will need to call Techline for a VCI number to allow them to change the calibration for the 20's. Techline will charge the dealer $50 for this, which they will no doubt pass on to you.

 

They will also have to set the tire size in the ABS or VSES (stability system), but this only requires going into the special functions section of the Tech 2 and picking a tire size. They don't have to call anyone.

 

Assuming you have tire pressure monitoring, they will have to recalibrate that, but that's also a simple process and one you could even do yourself. Plus, they should put a new tire pressure placard on the door beneath the original.

 

That's about it.

[gmcgrands]

Thanks for the information Very helpful.

 

 

Yes, the PCM has to be reflashed to maintain speedometer accuracy.  You can refer them to this TSB: 03-03-10-006C - Sales doesn't know squat about this stuff.  They only know how to sell it.  Service should know though.

 

They will need to call Techline for a VCI number to allow them to change the calibration for the 20's.  Techline will charge the dealer $50 for this, which they will no doubt pass on to you.

 

They will also have to set the tire size in the ABS or VSES (stability system), but this only requires going into the special functions section of the Tech 2 and picking a tire size.  They don't have to call anyone.

 

Assuming you have tire pressure monitoring, they will have to recalibrate that, but that's also a simple process and one you could even do yourself.  Plus, they should put a new tire pressure placard on the door beneath the original. 

 

That's about it.

 

<{POST_SNAPBACK}>