Knock sensor trouble

Phil1031 · November 20, 2016

NEED HELP! Please let me know if I'm not in the right place for this. I have dumped over $1000 on a reoccurring PO332 code. GM mechanics swear problem is resolver but light keeps SES light keeps coming on and code reappears.

Truck- 2006 Chevy 1500 w/t 5.3 flex, single cab, long bed, 2wd, 158000 miles

Full story-

May 2016 SES light comes on, take truck to Oreilly's and have code read. Knock sensor failure. (Don't remember code)

Purchased 2 Borg Warner KS, and new harness. BW KS $55 each, lifetime warranty, harness $30. Schedule appt at local ASE certified shop with a very reputable mechanic. $365 and new sensors and harness replaced. Drive truck all summer, no issues.

September 2016- light comes back on. PO332 code. Take truck back to same mechanic. He has truck for 2 days and determines that we should not have used after market sensors. We decide to pull the BW KS and replace with delcos. Delcos cost $95 each with 12 month warranty. Mechanic RE-uses harness. $190 for new sensors and another $360 for install. All is good for a week. SES light comes back on. PO332 code reappears. Truck goes back to mechanic. Has truck for two days. Opens everything up and checks all wire connections. Does diagnostic tests on sensors and circuit. Everything checks out OK. He can't find anything wrong. No charge. Tells me that if light comes back on, may need to replace ECU. Recommends if SES light comes back on to take it to dealership. Drive truck for 4 days, roughly 500 miles, light comes back on.

Truck goes to local dealership last week. $95/hr labor, they have truck for hour and a half, come back with "we fixed it". They found terminals on body side of harness were loose... tightened them to the tune of $150 and said that should take care of it. 800 miles later, guess what? SES light is back on and I'd bet this truck on what code it shows when the truck goes back to the dealership tomorrow. I've put over 110000 miles on this truck since I bought it and I can count the number of times the SES light has been on on one hand, and luckily I'm mechanically inclined enough to have fixed the issues myself.

My question to anyone out there that has experience with these things is:

What else could possibly be creating this code?

Could my PCM be the culprit?

I should also mention that every time the code was read, the codes were cleared from the PCM so the code wouldn't be reoccurring without an issue somewhere...

I will also mention, I've thoroughly checked the vehicle for mouse damaged wires. So did the first mechanic. There is none.

So very tired of throwing money at this issue to no resolve. If you have any information or experience with an issue like this, let me know what you think.

Sorry for the short story. Any help or info will be appreciated!

Dnt · November 24, 2016

Just a quick look around the internet shows that there is a GM bulletin on how to fix. It says something about moisture at the KR device causes rust and a ground failure. Just have to be sure to clean the well thoroughly (apparently you have to jump on top of the engine to get to the area properly) and add some silicone to seal it to keep it from reoccurring? They do recommend the OEM sensor as it seems that the aftermarket ones are not reliable and it take several hours to change these since the intake manifold has to be removed. Big arse hassle I would probably trade the silly thing in on a new Denali but that is just me!