Check engine light, traction control off, code P033D

I have a 2017 Tundra.

I am seeing these symptoms:
1. The check engine light is on
2. The dashboard screen is displaying a message: Traction Control is Off
3. The transmission won't shift into 5th and 6th gears
4. I took the truck to AutoZone and they read code P033D which is Knock Sensor 4 Circuit High Input

According to this thread, it is likely an animal chewed up the knock sensor wires.

I called my insurance company. They said it is covered damage if an animal ate the wires but not covered if it is normal wear and tear. They suggested taking it to a local shop to get an estimate. I did that, but the shop said they can't take things apart to do an estimate and they can't tell me anything because the wires are not visible.

So, now I have a problem. I don't know for sure if the damage is caused by an animal so I don't know if I will be paying for this out of pocket or not.

If insurance will cover it, I don't mind taking the truck to the dealer. But, if I am paying for it, I am not sure I want to pay their prices.

Does anyone know a repair shop in the North Dallas area that has seen these symptoms before and can help me diagnose the cause quickly?
Or, do you have any other suggestions?

 

The knock sensors, from what I understand, basically monitor engine vibration to detect when parts interact in a way that signals engine damage/wear, or detonation. Start with just opening up your engine bay and looking at all your wires and connections. Everything should be tight, and wires not frayed. Its even possible the sensor is bad, if something appears to have happened to it. Can you find knock sensor 4 in the engine bay and inspect it?

Bigger question.. does the engine run fine? Smooth idle, no shakes, knocking sounds or anything that sounds out of the ordinary? Usually you can hear a knock, if indeed that's what's happening.

 

Did they read the TCM as well?

 

Looking in the engine bay, I don't see any frayed wires.
As I understand it from reading on the forum, the knock sensor wires are beneath the intake manifold and there is some disassembly needed to get to them. I have not done that.

The engine runs fine. Smooth at idle, no problems during acceleration. No shakes or knocks. Only thing is it wont go into 5th or 6th gear so the RPM gets higher on the highway.

 

They only plugged a device into the OBDII port and told me the code.
I don't expect much more from AutoZone.

How would I read the TCM?

 

Oof, yeah that's a hard place to look at.

If the engine is running great then maybe it experienced detonation once or twice and that set it off. Can you see if there's any misfires logged on the computer? AutoZone probably won't have a scan tool good enough to check that. Do you remember driving when it occurred? Did you experience anything out of the ordinary or did the dash just light up with no warning?

Also, is your battery in good shape? Full charge etc

 

I don't have a scan tool, so I can't check that.

I was not driving. I noticed it one day when I started the truck to go to the gym. I drive it the day before, nothing out of the ordinary before or since. Like I said, it still drives as normal except for 5th and 6th gear.

Seems to be. The truck fires up with no hesitation when I turn the key.

 

Looking at the engine, it looks like an animal chewed away the foam on the right side (When facing the vehicle from the front) of the intake manifold:


From what I can tell from reading the forums, knock sensor 4 is toward the left rear (Again, looking at it from the front of the vehicle) of the engine. I snaked an inspection camera under the intake manifold and it looks like the wires to the sensor are frayed:

 

If you have the tools I'd recommend taking off the manifold and checking them further. A frayed wire can make the voltage drop across the sensor much different than it should be, which is what the ECU is monitoring. It has no idea if a wire is frayed or the engine is actually knocking, it only knows what it thinks the sensor is telling it.

If you found evidence of animal chewage, pretty likely that's your problem.

 

I agree. I will take it to the dealer and see if my insurance will cover it.
Thanks!

 

An update: I took it to the dealer. They removed the intake manifold and said they believe an animal chewed the wires. They are submitting an estimate to my insurance company now.

Thanks for the help everyone!

 

Let us know how you make out...

 

My insurance agreed to pay for the repair, less my deductible.
Toyota said my truck will be ready later today.

Thanks for all the help everyone!

 

Damn soy wires. Glad it worked out.