For the 2009 model year Tahoe the RPO code you would be looking for will be K5L. This is the Heavy Duty Trailering Package. Also the Z71 is not a trailering package. It is simply and off road suspension package. Also like SabrToothSqrl said the K5L pacakge comes with an integrated trailer brake controller. You could simply look for that and you would know (on a 2009 at the least) that it has this package. The 7 Pin trailer connector is standard on all 2009 Tahoes as well. I hope some of this information helps you.

Jeff Morris, Chevrolet Customer Service

 

Thanks for the replies, everyone. The Tahoe we ended up getting is a 2008 model, VIN 1GNFK13078R233295 -- the dealer assured me it had the heavy duty package, basing that on the Z82 code number. It has the 3.73 axle ratio (GT4), and active brake controller (JL4) but not the KNP transmission cooling system code (KNP) or the K5L.

I got a lot of conflicting information from a lot of people, and even though we have the vehicle and like it and I feel reasonably confident it has the heavy duty capability, I still am a little nervous about it. If anyone else can a look at the VIN (http://www.compnine.com/vid.php?vin=1GNFK13078R233295) and let me know your thoughts on it, I'd appreciate it.

Two others we were considering were a bit different. They were both 2007s, 1GNFK13087R295903 and 1GNFK130X7R124439 -- both have a 4.1 axle ratio and the KNP transmission cooling package, but NOT Z82 or K5L. I don't know if something changed between 2007 and 2008 to account for those differences, but it makes me nervous that the 2008 doesn't have that same axle or cooling package.

This is confusing!

 

according to the info, u have an 'active brake controller' but that (as far as I know) is an '09 option... and this was built early 08. Does it have it? It's by your left knee on the dash... two tabs you can squeeze together.

If you don't have the additional tranny cooler, they are not that hard to add, I put one on my wrangler when I went to 35" tires for 4-wheeling...

 

Hi Jeff, I have a 2007 Tahoe with the 3.42 axle ratio, Z71 package, 5.3 L V-8 OHV Sfi 16v ffv engine, 18x18 wheels, does this vehicle have the Oil/transmission cooler, I know it doesn't have elec brakes yet, but I'm gonna get those, just wondering if what else it needs.....and if it does need an aftermarket cooler for both the oil and transmission fluid, do you have a brand you recommend?