My honest opinion your average mechanic has piss poor soldering skills. And in piss poor tape,wrapping.... Moisture,corrosion would become a factor in around a year maybe less depending on seasons,climates

Weather pack connectors are idiot proof :) if not make dealer replace splices with heat shrink SOLDER butt splices. It's also for amateurs in wiring

 

Okay, done some searching and found both the Automatic Harness and the Manual Harness.

Automatic Harness runs: $364.30+CED Plug & Play Harness+Installation
Manual Harness runs: $238.71+CED Plug & Play Harness+Installation

GMPartsDirect and GMPartsHouse has both harness's for about $100 cheaper. So...if anyone is interested in getting rid of their "hacked" harness....it's going to cost ya...

Plus....will it really "fix" your problem?

Automatic Part# 25994656
Manual Part# 25994657

And a link including a diagram:
http://parts.nalleygmc.com/showAssem...&searchString=

 

I was planning on the LNF upgrade on my 09 auto and about that time the key got stuck in the ignition. $378 later its back to normal. After harassing the dealer thru GM CS, they are supposedly refunding half.

 

It depends on what you expect.

I got tired of the inconsistency, though I believe my final solder was working fine, I just know that with my car and many others, what works fine today can change in a heartbeat tomorrow.

I firmly believe if you haven't had a problem with the stage 1 upgrade you eventually will.

After splicing, motor mounts, rotors, moving up the IC, a new fuel pump all at 21,000 miles I felt it was worth buying a new harness the connectors and paying it to go on. My total bill was less than quoted here, with $236 for the install and something like $270 for the harness and connectors.

When my transmission froze this week I decided I'd just about had it. The dealer and GM finished the repair today, though I instructed and will pay the dealer to go through the car top to bottom, I actually said from headliner to wheel bearings to make sure nothing is close to breaking again.

I work crazy hours and when I drive I want to enjoy it.

Life is too short.

Now I said it before, I may sell this car soon, but I wasn't going to turn over my problems to someone else, not without doing everything I can to make this car right.

IMO

 

how hard do you think it would be to install the harness yourself??? I'm not a mechanic.....I work on cars...ALOT....just trying to save a little money where I can...

 

Shawn let me check my price on a manual harness for you, if you don't hear from me shoot me a text and remind me, # is on FB.

 

That would be awesome Joe, I have your number saved in my phone. Shoot me a text too, my # is on my FB as well

 

said heck with it....

I went ahead and ordered a BRAND NEW engine harness along with the CED plug & play GMS1 connectors. Atleast I'll know that I won't have any splices...and it'll be weather resistant...not having to worry about corrision.

Still not sure if I should tackle putting the harness in or have it done. Heck.....all it is is a bunch of wire with connectors....really shouldn't be that hard...just time consuming..

I'm going to go ahead and order ZZP's coldside pipe as well....looks like it puts the location of the lower MAP sensor up by the throttle body...no worries about fitment issues or wires getting pinched.

Will it fix my problem? I highly doubt it...but aleast I know the wiring isn't the issue

 

I'm hoping it will do the trick, I think the lower sensor has to do with the erratic boost. I haven't got to check mine for a while, but the erratic boost and surging idle has returned. Last time they replaced the lower sensor and the release valve, and it fixed it. Keep us posted.

 

Got my CED GMS1 harness today....

Now, I'm just waiting on the new engine harness to come in. Ended up getting the Automatic harness for $280 plus tax (wholesale) from a local dealer. I'm hoping I can install it myself....shouldn't be to hard...just time consuming. I also talked to another GM mechanic today about my issue. He said "if it were a sensor causing your problem...you would definently get a code/CEL...I really think it's a wiring issue since you're not getting any codes". Hoping this new harness, CED connectors, and a new lower ZZP charge pipe (to relocate the lower MAP sensor) will do the trick. If it does....I'm havin' an F'n party and EVERYONE is invited!