2002 Yukon/Another knock sensor thread

[alpha_omega]

Here’s what I think I learned with the knock sensor saga over the last several months on my 2001.
AC Delco are the best choice in KS parts.
But read somewhere that 50% of those are faulty out of the box.
Be sure to dam the sensors after installing to prevent moisture infiltration. There is a TSB on this.
Idling does not complete the drive cycle so that’s why the codes show up later after a roadtrip.
Replacing O2 sensors may or may not help. Didn’t for mine.
What finally seems to have fixed mine after the third go round of KS was replacing the Mass Air Flow Sensor.
Since that was done no KS codes and not pending either.
Yukon runs much better but still chasing other gremlins.

x2 on this one. Use ACDelco for the KS.
The dam is a very important step. Don’t avoid this one.
I was lucky in that replacing the O2 sensors as well as just cleaning the MAF Sensor was all that I needed. No KS codes since then.

 

[alpha_omega]

I did a write up for this on my ‘02, back in like 2007-2008. For one reason or another I can’t seem to track it down. If you need photos let me know and I’ll see if I can dig them out of the archives.

 

[The Hurt Guy]

I am new here and not a professional. I own a 2002 Yukon with a 5.3l Z engine. I had the 0327 code first in March '23 and accepted that due to age I needed to just replace both KS. Finally had them replaced in prep for a November Emissions inspection. First were after-market; after the drive cycle, returned with a 0332 code. The wiring harness was blamed, and replaced. After a drive cycle, CEL returned with a 0327 again. The mechanic tried a 'flip' of the harness to see if the code reversed. The code did reverse. Shop opted to replace/warranty both KS and the wiring harness, using AC Delco sensors. After the drive cycle, CEL returned with 0332. The mechanic recommended the replacement of the ECM. Bought a refurbished ECM from Flashmasters, and flashed it to the VIN for the vehicle. After the drive cycle, now BOTH 0327 and 0332 are sending. Coincidentally, now the ABS and Brake light illuminate within 2 minutes of driving, and I accept that the original EBCM is needing replacement.

After learning from this thread and others here, I see I need to thoroughly clean the connectors at the ECM, as the mechanic reports all added components are testing at acceptable continuity - leading to a suspect fault in the wiring between the harness and ECM (as in the video) or issue with oxidization in the pinned plugs on the ECM. I will share what happens next.

 

[Eldiablo]

I've been reading knock sensor posts and watching videos for 3 days and I'm really in need of some direction. I have a 2002 Yukon with a 5.3. It was throwing a knock sensor code. It was only one but I don't remember which. I watched some videos and ordered two new sensors and a new harness on Rock Auto (not AC Delco but good reviews). I did the swap and it all went well. Cleared the codes and let the truck idle about 15 minutes. No codes. I then drove about 30 miles and parked it. About 2 hours later I got back in and started driving. After 5 miles I got P0327 Current fault and P0332 Pending Fault. So I've been doing more research. It sees a lot of people recommend getting OEM sensors. So I went to my local Chevy dealer and bought 2 ACDelco sensors and a new AC delco wiring harness. I really don't like just throwing parts at this and I really really don't want to pull it all apart again just to have the same issue so I looked up how to test the KS.

I found this video

So I decided to test my original sensors vs the new ACDelco ones I bought. Resistance on the new ACDelco ones were right at 99 ohms. The original ones were about 108 but jumped around. Ok I guess that makes sense. Then I did the hammer tap voltage test. The original sensors registered 0.02-0.05 V. That seems low but both were reading something. Finally I did the hammer test with the new ACDelco and got nothing. I tried over and over with both new sensors and get no voltage at all. Could both be bad right from the dealer?

Now I don't know what to do.
Pull it apart and try the new ACDelco stuff and hope for the best?
Take these back and try another dealer and see if those pass the bench test?
I've seen people talking about putting in a resistor to test and see if there is an issue on the ECU side. Should I try that route?
I could try hooking up the new ones outside of the intake (would have to ground them) and see if I get the codes back. Not sure if this would work
Test me RockAuto non ACDelco sensors just to see what they say.

Would appreciate any help.

relocate them from under the intake to the heads.

 

[Fless]

relocate them from under the intake to the heads.

The OP hasn't been on here since July 2nd.

 

[Marky Dissod]

relocate the knock sensors from under the intake to the heads.

The OP hasn't been on here since July 2nd.

Agreed, but the info would still be helpful to others ...

 

[Fless]

Agreed, but the info would still be helpful to others ...

Agreed, but some detail on how it could be done would be even MORE helpful.