Knock Sensor Questions

So today I got error code P0333 - Knock Sensor 2 Circuit High Input (Bank 2). This is on my 2012 V6 with 82000 miles. I bought the vehicle used from a dealership this last may, and I still have a limited warranty. I'm going to go Saturday and see if they will cover this under the warranty (not counting on it).

So, my questions are:

• What are the risks/concerns if I have to drive it a few days before I can fix it? Other than the obvious that the sensor won't be able to detect issues in the engine, will running with a potentially failed sensor doing further damage?
• 
  
• If it's not covered under the warranty, what are the procedures/steps to replacing it myself? I know I'll have to remove the manifold. I can turn a wrench and have helped with some motor work in the past, but I'm not a mechanic by trade. I would need a video, instruction guide, or pointers on the process to get it changed.

Thanks for the help

 

When a chipmunk gnawed the wires to the knock sensor on my truck, the tranny eventually ended up not going into 5th/overdrive.

To replace them is a big job. The top of the motor has to come off. Search for knock sensers here and you will see what it takes to do it yourself. A dealer is going to cost you upwards of $2000 I bet now days. Mine was quoted at $1800 a few years ago.

 

Hopefully it's just the harness for them. Any signs of rodents in the engine bay?

 

Mice, rats and squirrels love them some knock sensor wiring....

 

No, none. I live in suburbia and it is garage kept, and as far as I know there's no rodents in my garage.

 

So, not covered in the warranty. Not surprised.

Do I still need to pull the manifold just to check/replace the wire harness?

 

https://www.tacomaworld.com/threads/knock-sensor-replacement.235717/#post-5583917

 

Thanks. I've read that thread multiple times, as well as every other thread on these forums I can find regarding knock sensors. I was looking for clarification to my question.

 

Is drivability ok? Doesn't run rough or anything? I haven't done one in a while but it be easier to remove it. And just look into the valley past the coolant pipes and hopefully you'll see damage to the harness.

 

Drivability is fine, except it won't shift from 4th to 5th.

 

Drivability is fine, though it won't shift from 4th to 5th.

I found this picture in another thread. Is this really the steps to get this job done?

 

To replace the sensors yeah I believe so. You need to remove the heads. If its just the harness you can get by with removing the harness with some picks with just the intake off. I've never actually done the sensors. Only harnenesses due to rodents.

 

Thank you. That's what I wanted to hear. Now I need to see if I can find the wires.

 

I didn't see any signs of wear on any wires or harnesses. Of course, I'm not sure which one leads to the knock sensor, but every wiring harness I can see looks fine.

I did try to reset the CEL, just in case, by disconnecting the battery for a few seconds. When I reconnected and start, the truck ran for 2-3 seconds with no light, then died. Started it again, and the Cal is back on.

 

The truck dying after the battery being disconnected is normal. The fact that the light came right back on indicates a hard fault. It's tough to find the little sub harness if you don't know what you're looking for.

You should be looking at this, once the intake plenum and minfold are removed. The sensors are below those two pipes in the middle. You'll be able to see if the wires are damaged from here. Is this still exploratory or do you have parts on hand? Also if you replace the sensors, get toyota ones. Yes, they're super expensive, but it beats having to pull everything apart again.

 

I'm just making sure I rule out other possibilities before I either dig into it or pay out the butt for someone else to fix it.

 

Yeah it sucks if it's the harness it pays the same time to remove the heads, something like 15-16 hours, which depending on how much shop labor an hour is, is close to $2k.

 

Well, found the problem. Wire broken right at the connector. Unfortunately, none of the local parts stores sell them, and the Toyota Parts department closes at 3 on Saturdays. I have to wait until Monday to get a new wiring harness.
Anyone know how to test the sensor while I wait? I tried hooking up an ohmmeter to the two posts, but got no reading. Don't know if that means that I'm testing it wrong, or if the sensor is bad too. Seems odd that the sensor would go bad at the same time that the wire broke, but don't want to put it back together and have to take it all apart again. There again, I hate paying all that extra money for a new sensor if I just tested it wrong.

 

I'll try and look up how to test it, but if you decide to replace them, use Toyota parts. I've worked an an older Avalon that went through 3 total aftermarket sets, I replaced 2, before they finally decided to listen and use oem parts. They cost a lot more, but not worth the headache imo.

 

Edit: it says 2wd but it's the same for 4wd and pertinent. Same 1GR engine