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Posted

First off, I've searched this site and all over the interwebs. Many others have had this problem, but nobody has reported a fix.

 

So I replaced the knock sensors in my 2002 5.3 liter Suburban last month. As to be expected, the rear hole was full of water. Got everything back together, had code cleared, truck ran great. Then the code came back on. So I went and bought a $100 code reader at the evil empire (Wal-Mart). Lately, I've just left the code reader plugged in, sitting in the cup holder, as every other run cycle I have to clear codes P0332 and P0327. When the MIL comes on, the computer retards timing a few million degrees, so I hit the button on the code reader to erase the codes so my truck will run normal. There is NO knock that I've heard, and the truck is running great when the light is off.

 

So, I've replaced the sensors, truck runs great, but the computer keeps throwing these two codes. Has anyone figured out a definite fix for this, other than the obvious "check the wires/connections?"

Posted

Did you replace the short wiring harness between the engine harness and the two sensors? Have seen problems with them. Check the resistance. Should only show a couple tenths of an ohm resisance.

Posted
Did you replace the short wiring harness between the engine harness and the two sensors? Have seen problems with them. Check the resistance. Should only show a couple tenths of an ohm resisance.

 

Sure did. Replaced both knock sensors, wiring harness, rubber grommets, and sealed them up nicely with black RTV.

Posted

Did you torque the sensors as these sensor are very easy to damage unknowingly if over torqued causing all sorts of problems. They should torque at a minor 15ftlbs.

  • 1 year later...
Posted

I have the same problem on my 02 Silverado 2500HD 4x4 replace both sensors and wiring harness, cleared codes, codes come back. Did adjusting the torque on the sensors fix the problem or was there something else done? Any info is appreciated thanks.

  • 2 weeks later...
Posted

First off, I've searched this site and all over the interwebs. Many others have had this problem, but nobody has reported a fix.

 

So, I've replaced the sensors, truck runs great, but the computer keeps throwing these two codes. Has anyone figured out a definite fix for this, other than the obvious "check the wires/connections?"

 

Same situation here...

2000 Yukon XL 5.3

I'll bullet what I've done..

-Got one of the standard knock sensor codes and CEL

-Replaced both knock sensors and the wiring harness, properly cleaned and torqued etc.

-BOTH pending codes P0327 and P0332 come up within a couple minutes of running after every time I reset them. (Yes, they are plugged in, it's the first thing I checked!! :)

-CEL comes back on in about 15 miles with 2 warmup cycles

-I have cleared the codes, and disconnected the battery to clear everything out, and they still come back.

-99.7 Ohms at with truck off

-109.9 Ohms with engine idling. Both sensors are within a tenth or two measured at the plug end of the new harness. Seems in an acceptable range or operation.

Checked wiring back to harness, and roughly checked under the fuse box to make sure nothing has been living in there and feasting on my wires, it was clean.

 

Any answers yet? ECM? Other way to check the sensors? I used the KT116 sensors, could this be the problem even though they seem to check out?

 

Thanks!

  • 2 weeks later...
Posted (edited)

I used the KT116 sensors, could this be the problem even though they seem to check out?

 

 

Found the problem! The KT116 sensors don't play well with the truck. I changed to ADCelco 213-3521 sensors and the same new harness I used and everything cleared up within 40 miles. The job was much easier the second time, but still a pain!

They ohmed out at 99.9 and 100.0 ohms, I didn't check them running.

The tank of gas I ran with the knock sensors out of wack was just over 10 mpg! EEK! Timing advance under moderate acceleration with the bad sensors was around 4 to 8 degrees. With the ACDelco it was around 16 to 25 degrees. I am assuming that is quite a hit in power and efficiency.

 

Noah

Edited by jlkfg
  • 4 years later...
Posted

Hi,

 

I know this thread has not been updated in 5 years, but I just wanted to throw in my $0.02, and I created an account just to do it.

 

Here was my issue, and solution:

 

Code P0327, and it would come back after 2 drive cycles. (front knock sensor, low voltage).

 

Rather than pulling the manifold, I threaded the new sensors into the front of the left head, and hooked the new harness to them. I bought the two knock sensors on eBay for $10 total, and the harness for $15. I started getting low voltage codes on both sensors. I replaced both sensors with two more brand new ones, from a different manufacturer ($25 total on Amazon). Still got the low voltage codes on both.

 

So far, I was into this a total of $50, and all 4 sensors still gave me low voltage codes. Aftermarket cheap sensors DO NOT WORK.

 

Back to square one.

 

I refused to remove the manifold without knowing EXACTLY what the issue is. I knew that the front sensor was the problem, so I spliced the wires and reconnected the rear knock sensor back into the wiring harness, and then removed the foam from the front underside of the manifold. You can reach in and touch the front sensor (and maybe even the rear) without pulling the manifold. I made my own wiring harness and attached it to the front sensor. I ran the wire up over the top of the manifold and spliced it into the wiring harness. So the rear is hooked up normally, and the front has a home made wiring harness. Still using the original knock sensors. Drove the rig for 3 hours on and off the freeway, shutting off and restarting the engine 6 times during that process. NO CODES AT ALL!!! Not even pending codes. Turns out that the front sensor wiring was bad, and could be fixed for the cost of a 12 inch piece of wire, and a couple universal wiring connectors.

 

Had the knock sensor actually been defective, I would have bought the original expensive OEM factory knock sensors. Then I would threaded it into the cylinder head, near the oil filler cap. Hook up the new wiring harness, and that's it. There are several threaded holes on the cylinder head that will accept the knock sensor. No one should need to pull the manifold to solve this problem. Relocating the knock sensors is not going to cause a problem. I have done it several times on different vehicles, and never had a problem even after driving it for years.

 

Hope this helps some of you guys out.

  • Like 1
  • 1 month later...
Posted

Hi,

 

I know this thread has not been updated in 5 years, but I just wanted to throw in my $0.02, and I created an account just to do it.

 

Here was my issue, and solution:

 

Code P0327, and it would come back after 2 drive cycles. (front knock sensor, low voltage).

 

Rather than pulling the manifold, I threaded the new sensors into the front of the left head, and hooked the new harness to them. I bought the two knock sensors on eBay for $10 total, and the harness for $15. I started getting low voltage codes on both sensors. I replaced both sensors with two more brand new ones, from a different manufacturer ($25 total on Amazon). Still got the low voltage codes on both.

 

So far, I was into this a total of $50, and all 4 sensors still gave me low voltage codes. Aftermarket cheap sensors DO NOT WORK.

 

Back to square one.

 

I refused to remove the manifold without knowing EXACTLY what the issue is. I knew that the front sensor was the problem, so I spliced the wires and reconnected the rear knock sensor back into the wiring harness, and then removed the foam from the front underside of the manifold. You can reach in and touch the front sensor (and maybe even the rear) without pulling the manifold. I made my own wiring harness and attached it to the front sensor. I ran the wire up over the top of the manifold and spliced it into the wiring harness. So the rear is hooked up normally, and the front has a home made wiring harness. Still using the original knock sensors. Drove the rig for 3 hours on and off the freeway, shutting off and restarting the engine 6 times during that process. NO CODES AT ALL!!! Not even pending codes. Turns out that the front sensor wiring was bad, and could be fixed for the cost of a 12 inch piece of wire, and a couple universal wiring connectors.

 

Had the knock sensor actually been defective, I would have bought the original expensive OEM factory knock sensors. Then I would threaded it into the cylinder head, near the oil filler cap. Hook up the new wiring harness, and that's it. There are several threaded holes on the cylinder head that will accept the knock sensor. No one should need to pull the manifold to solve this problem. Relocating the knock sensors is not going to cause a problem. I have done it several times on different vehicles, and never had a problem even after driving it for years.

 

Hope this helps some of you guys out.

This is fantastic information!! Thank you so much for sharing it! Is there any way you could take some pictures and show the alternative locations and how you work around the manifold?? Also could I see pictures of how you made the alternative wiring harness? Sorry for all the questions, I am desperate to fix this and I don't want to figure out how to pull the manifold if I don't have to.

 

Sent from my SM-J320V using Tapatalk

  • 1 month later...
Posted

I'm having the same exact problems but now. I have a 06 chevrolet. I have changed out my knock sensors and harness. The engine light is still on and been driving it like that. Just yesterday and today every time I start my truck it sounds like my battery is dead then it starts up after a second or so. It's not my battery going dead.i had it checked at auto zone and its good. Just want to know if any has had these similar issues or has any suggestions.

Posted

Did you clear the codes after replacing the sensors? Even if you fix the problem, the check engine light will stay on for a certain number of engine cycles before it clears the code automatically. Disconnecting the (-) battery for cable for 5 minutes with the ignition on, will clear the codes immediately. If you did clear the codes and they are returning repeatedly, what are the circumstances that trigger the light? Letting off the throttle at freeway speeds is a common time that the check engine light will click on if its a low voltage code.

 

As for the slow cranking starter that picks up speed, it sound to me like you have either a weak starter that will fail soon (brushes are stuck or worn out) , or its a bad connection on the (-) and/or (+) starter wires. If the starter does fail completely, have someone hold the key in the "crank" position, while you rap on the side of the starter with a wrench or very small hammer. Tap lightly at first, and don't ever hit it real hard. Your not driving nails into wood, your using the vibration to free up a stuck brush spring inside the starter. Don't hit the solenoid or any of the electrical connections! The tapping almost always works a half a dozen times or so and then it stops working all together. Use this method a few times max and then replace the starter.

  • 4 years later...
Posted

First of all I have been through this. Here is a link to look at for relocation https://www.jegs.com/i/ICT+Billet/335/551216-KN30/10002/-1?gclid=CjwKCAjw-sqKBhBjEiwAVaQ9a-UQmnukjdd_SPaAfu7jAUpLhmLZ-VYiqnew745fOvtRRSmXcDqCPxoCeVYQAvD_Bw. Also use only AC DELCO sensors as other ones tend to be hit or miss on setting codes. I only relocated my passenger side sensor as it was the bad one. I relocated mine to the front of the passenger head where there is already a threaded hole the knock sensor will screw into.  Amazon has Ac DELCO sensors for 38.00 each. I bought the correct connection to snap on the sensor at AutoZone and ran it to the sensor connector at the back of the intake manifold. I cut the light blue wire behind the connector and soldered this wire to it. The light blue wire is for the passenger side connector. I left the dark blue wire alone as the driver;s side was not throwing a code. If the driver;s side does throw a code there is a threaded hole by the spark plug I will use. Or you can buy the relocation  blocks at the above link.  My Tahoe is running fine with no codes.

Posted
23 hours ago, turbo15479 said:

First of all I have been through this. Here is a link to look at for relocation https://www.jegs.com/i/ICT+Billet/335/551216-KN30/10002/-1?gclid=CjwKCAjw-sqKBhBjEiwAVaQ9a-UQmnukjdd_SPaAfu7jAUpLhmLZ-VYiqnew745fOvtRRSmXcDqCPxoCeVYQAvD_Bw. Also use only AC DELCO sensors as other ones tend to be hit or miss on setting codes. I only relocated my passenger side sensor as it was the bad one. I relocated mine to the front of the passenger head where there is already a threaded hole the knock sensor will screw into.  Amazon has Ac DELCO sensors for 38.00 each. I bought the correct connection to snap on the sensor at AutoZone and ran it to the sensor connector at the back of the intake manifold. I cut the light blue wire behind the connector and soldered this wire to it. The light blue wire is for the passenger side connector. I left the dark blue wire alone as the driver;s side was not throwing a code. If the driver;s side does throw a code there is a threaded hole by the spark plug I will use. Or you can buy the relocation  blocks at the above link.  My Tahoe is running fine with no codes.

Soldering wires throws off the values used by the computer to make corrections.

  • 3 months later...
Posted

OK just joined up, I am working on a friend’s 03 Silverado. New sensors, seems like the harness had already been replaced so I didn’t replace it. Since the problem is both sensors and there are two wires I don’t think it’s the harness at the connector to the sensors. Checked the resistance at the connector very close to 1.0. 
want to.know if someone has the info for the corresponding pins on the main ecm harness, Also if anyone else has had success with going to ADCelco 213-3521 from aftermarket. 
Also has anyone noticed if humidity changes anything. Didn’t have an issue foe several weeks of on and off use then it rained yesterday when I was taking it for what I thought would be the last test drive and the check engine light came on. Back to the drawing board

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