P0332 Knock Sensor 2002 Sierra..help !

[noahraysanders]

My local dealer replaced the knock sensors. The lights went out an the truck seems to be running fine.Thanks for everyones help

 

We're here to help and hassle! Post a pic of your truck and come back again!

 

 

What purple cleaner did you use to clean off the lubricant off the wireharness plugs?

[2500sierra]

if your talking about the big rubber plugs, and trying to make RTV stick to them...well i just used some brake cleaner on them and wiped them off with a rag, that took all the packing oil off.

[joshbazanjosh]

I have a 2002 gmc yukon 5.3 v8, the truck gave me the check engine light and it was the knock sensor codes, i took it to my mechanic and he said that it needs new knocking sensors, so he replaced the knocking sensors and wireing harness and intake gasket. he cleared the codes and the codes came back , he cleared the same codes and came back again . he check the wires going to the computer and he said that there was no voltge, and he said that computer is bad and needs to be replaced. so i replaced the computer and still the codes came back again.. i took it back to him and he took out the intake again and check if there was any mistakes but there was none. everything was installed right. he called me and told me that he had tryed eveything but doesnt know why its doing that. i dont know what else to do. Does everybody know why its doing that please send me a message.

 

 

josh

[noahraysanders]

if your talking about the big rubber plugs, and trying to make RTV stick to them...well i just used some brake cleaner on them and wiped them off with a rag, that took all the packing oil off.

 

 

thanks

[skiplaubach]

I am a brand new member due to the discussion on the knock sensors. Yesterday, I changed mine out on my 2002 Silverado 5.3L. Agreement with all previous posts. I will add the following:

 

1. the electrical connector to the knock sensor is a bit of trick to remove. As observed in prior photos (excellent photos), the knock sensor top is a round, white disk with the electrical pin in the middle. The electrical housing that covers this is oval in shape. Not mentioned yet is the removal method (and is not mentioned in Chiltons). Being oval in shape, pliers (standard shape) are used to squeeze the elongated ends of the oval into a round shape. Squeezing the oval allows clearance of the electrical connector to be lifted up from the white round part of the sensor. Hope this helps as I spent about 45 minutes figgering this out.

 

2. My problem, the check engine light indicated a bad sensor. I discovered an abandoned mouse nest in the compartment under the intake manifold with lots of litter. The back sensor was clean but the front sensor was surface rusted and corroded (not quite as bad as the prior photos). Plus, the wiring was chewed "into", exposing bare wire. So, I vacuumed up well, cleaned the surfaces, replaced both sensors, replaced the gaskets, and electrical taped up the exposed wire (did not have new wiring harness, darn it!).

 

3. After reassembly, the truck started right up and the check engine light never came back on (100 miles so far). Looking forward to checking the gas mileage at next fill up. Engine seems to sound much "tighter".

 

Regards,

 

Weekend Wrench

[brasskey]

Thank you for the walkthroughs. This will definitely help me once I get around to replacing the parts. Anyone happen to have the part numbers handy for the sensors, gaskets and wire harness on a 2003 Tahoe (5.3L)? I found the following part numbers (couldn't find wire harness) and I wanted to double check them:

 

GM Part Number: 89060413

Manifold Gasket

 

GM Part Number: 12589867

Knock Sensor

[COREYHD]

WIRE HARNESS 12601822

[MatthewNeill]

I have a 2002 gmc yukon 5.3 v8, the truck gave me the check engine light and it was the knock sensor codes, i took it to my mechanic and he said that it needs new knocking sensors, so he replaced the knocking sensors and wireing harness and intake gasket. he cleared the codes and the codes came back , he cleared the same codes and came back again . he check the wires going to the computer and he said that there was no voltge, and he said that computer is bad and needs to be replaced. so i replaced the computer and still the codes came back again.. i took it back to him and he took out the intake again and check if there was any mistakes but there was none. everything was installed right. he called me and told me that he had tryed eveything but doesnt know why its doing that. i dont know what else to do. Does everybody know why its doing that please send me a message.

 

 

josh

 

I have had the same problem with my 2001 Yukon XL 6.0... I took every thing apart as per the previous posts, cleaned everything up shiny new, replaced the Knock Sensors, Wiring Harness, RTVd the caps, new intake manifold gasket, valley cover gasket, valley cover grommets, valve cover gaskets (the old ones were leaking a bit...) got it all back together again... Seemed to work like a charm for about two weeks... Seemed like I have been getting better gas mileage and less pre-detonation knocks...

 

(My engine has always been a little knocky, esp when I accelerate under load... I live in Phoenix, AZ and they use methane in our gas... Whenever I take a trip out of the Valley and user different Gas the knocking seems to subside a bit... also summer time is worse, it was 109 and the trouble code came back along with the knocking)

 

I think that my sensors have been bad for many thousands of miles… I bought the truck new on 01 and I have always keeps a clean engine, pressure washing every three or four months… Too bad there isn't a big warning label that says don't pressure wash… Maybe I should sue GM… Oh right… they went bankrupt…

 

 

 

But now that all this work has been done I am still getting the P0332 (Rear knock under volt error)... I am really frustrated that this error code keeps coming up... It appears to get triggered on a deceleration, i.e accelerating over a hill and then letting off the gas, then the error codes comes on… I guess it could have been from the acceleration over the hill… I just don't know… Is there anything else to replace? (Don't say the vehicle…) Would this be the sign of a defective replacement knock sensor? Has anybody else had the DTC come back after replace the knock sensors?

 

 

 

Also when I had everything apart I found a tacky-oily-carbony-sooty residue all through out the inside of the intake manifold… pretty much going all the way to the inside plane of the throttle body… I cleaned the intake manifold off (pressure washing of course…) I also noticed this residue down the intake ports and by the intake valves… I wanted to take the heads off and get them cleaned and rebuilt at a machine shot but just could afford all that down time now…

[2500sierra]

I am a brand new member due to the discussion on the knock sensors. Yesterday, I changed mine out on my 2002 Silverado 5.3L. Agreement with all previous posts. I will add the following:

 

1. the electrical connector to the knock sensor is a bit of trick to remove. As observed in prior photos (excellent photos), the knock sensor top is a round, white disk with the electrical pin in the middle. The electrical housing that covers this is oval in shape. Not mentioned yet is the removal method (and is not mentioned in Chiltons). Being oval in shape, pliers (standard shape) are used to squeeze the elongated ends of the oval into a round shape. Squeezing the oval allows clearance of the electrical connector to be lifted up from the white round part of the sensor. Hope this helps as I spent about 45 minutes figgering this out.

 

2. My problem, the check engine light indicated a bad sensor. I discovered an abandoned mouse nest in the compartment under the intake manifold with lots of litter. The back sensor was clean but the front sensor was surface rusted and corroded (not quite as bad as the prior photos). Plus, the wiring was chewed "into", exposing bare wire. So, I vacuumed up well, cleaned the surfaces, replaced both sensors, replaced the gaskets, and electrical taped up the exposed wire (did not have new wiring harness, darn it!).

 

3. After reassembly, the truck started right up and the check engine light never came back on (100 miles so far). Looking forward to checking the gas mileage at next fill up. Engine seems to sound much "tighter".

 

Regards,

 

Weekend Wrench

 

On mine i noticed it was more responsive and it took alot less peddle to maintain speeds like 40, and 65

[alwcurlz]

I'm glad this topic is helping a lot of people! I still have yet to get mine replaced though!

 

I still need the wiring harness for the knock sensors and valley pan gasket. My truck is still valve clattering under load while on the road, and less responsive than my brother's truck which had his knock sensors replaced. His truck has 190,000 miles, mine has 142,000. Hope this will fix my valve clatter.

[2500sierra]

i know this is turning into a beast of a thread

[Yotaman]

I paid to have my 01 Silverado 4.8L Engine fixed when it had this issue. I now have a 06 GMC CC with the 5.3L engine. Did they correct the problem in later years or will I have to face this again ?

 

Thanks,

Yotaman

 

I haven't washed this engine, I used to wash my 4.8 (Not pressure washed though)

[skiplaubach]

Regarding #3 in my previous post, the check engine light appeared at about 102 miles post knock sensors' change. I had it coded at Autozone and it's the sensors...or more likely the wire harness. As mentioned, my wire harness had exposed wire where mice had chewed through. I taped it up with electrical tape on a prayer, but no go.

 

So I've been googling for a wire harness and have thus far struck out.

 

Can anyone provide a link to an online store to purchase a knock sensor wire harness for a 2002 Silverado 1500 5.3L? And any advice on the connector location?

 

Much thanks,

 

Weekend Wrench

[skiplaubach]

One more item...any torque spec on the knock sensors themselves? I read a post somewhere that stated that over-torque or under-torque can cause the check engine light to reappear even after changing the sensors.

 

Thanks,

 

Weekend Wrench

[skiplaubach]

One more item...any torque spec on the knock sensors themselves? I read a post somewhere that stated that over-torque or under-torque can cause the check engine light to reappear even after changing the sensors.

 

Thanks,

 

Weekend Wrench

 

I'll answer my own questions:

1. GMGenuineparts.net has 5.3L Knock Sensor Wiring Harness, part # 12601822; $33.68 plus shipping.

2. (from another forum), knock sensor torque should be 15 lbs.

 

Weekend Wrench