Knock sensors replacement - recommendations along the way? (P0330) (1 Viewer)

[nicories]

Hey everyone,

I'm getting P0330 CEL, I've reset it a couple times and it comes back after about 20 miles. Looks like I'll be digging into the engine in a few weeks.

After some searching it seems most people replace or rebuild their starters at the same time. Other than the starter, and single-use gaskets along the way, are there any other recommended parts to replace? Vehicle has about 106k miles on it.

PS: I'll be doing general maintenance as well, spark plugs, etc.

 

[awesomeissquid]

Depends on how deep down the rabbit hole you want to go. Could consider getting your fuel injectors serviced at the same time. Maybe do the fuel filter if it has not been done. Also good time to give the throttle body a deep clean on both sides. Can't hurt to clean the intake manifold which typically will have some oil from blow-by.

 

[Mike NXP]

On the flipside if someone ( in my near future ) is going in to replace a starter, should they replace knock sensor while in there? I didn't realize that's where it was. Isn't there also some coolant sensor?


What about the clip / harness on the starter? I've seen some mention of that thing breaking off from being brittle, may want to look into that a bit.

 

[2001LC]

Most important is per-cleaning top of engine. In particular the area between heads and intake manifold. Any dust (sand) getting into intake ports, is a compression killer.

Replace any gasket removed.

Some like to take opportunity to replace water bypass joints front and rear gaskets.

You'll like be doing wire splice repair. As rodents chewing wire(s) of knock sensors is number one reason for a P0330.

Starter wire housing block, is good to have on hand:

I finish up vacuuming ever intake port of head.

 

[Mike Beauford]

Nice thread with great pictures and info. Thanks for posting.
My vehicle is a 2005 100 Series with 253K miles on it.
Back in May, the CEL P0330 "- Powertrain Knock Sensor 2 Circuit (Bank 2)" code popped up. After researching on MUD and youtube, I pulled the intake manifold, swapped both Knock Sensors with new OEM sensors, replaced the crispy plastic connectors that disintegrated on touch, replaced the perfectly good starter that had 253K miles on it on general principle. The CEL cleared and all was good until yesterday. The CEL light came on again and the exact P0330 code popped up. Since I have 2 new OEM knock sensors installed with new connector bodys, I am thinking the Bank 2 Sensor is probably actually detecting an out of range knock that it is alerting me about.
My question, is what should I do next? Do nothing and just watch it? Replace the engine if it goes catastrophic?
Any inputs appreciated.

 

[excessive]

100% reccomend to do your starter while you're in there. Also the connectors are a must, they will disintegrate as soon as you touch them

 

[Mike Beauford]

I have already changed my starter and replaced all the connector housings. I observed while driving yesterday that while driving at highway speeds the CEL light went off but came back on again when I slowed down at a stop. I am particularly interested if anyone has details on the CEL process. Does having a P0330 Knock Sensor CEL on put any changes on the engine (such as a limp mode)? I am not detecting any difference in how the engine runs or handles but could be wrong.

 

[white_lx]

The CEL light came on again and the exact P0330 code popped up. Since I have 2 new OEM knock sensors installed with new connector bodys, I am thinking the Bank 2 Sensor is probably actually detecting an out of range knock that it is alerting me about.

According to the FSM, the code description of P0330 is "No knock sensor 2 signal to ECM with engine speed between 1,700 rpm and 5,400 rpm". The code does not indicate knocking, but rather a lack of a proper signal at normal engine operation aka background noise. These sensors are like accelerometers and the ECM should see some signal during normal engine operation. Frequency of the signal should follow engine rpm. The P0330 code is a warning that knocking could possibly not be detected if knocking occurred.

There can be 3 reasons for this code: broken sensor, wiring issue, or a bad ECM. Since you replaced the sensors, my bet is on a wiring issue. If you look up the code in the FSM it has a test procedure that has you switch L&R through rewiring connector EC1 which is accessible without removing the intake manifold (not familiar with the exact locating of EC1, but it looks to be on top of the wiring at the rear of the engine).

Easiest way to diagnose would be to scope the L and R signals at the ECM and compare them. Alternatively, inspect the wiring. Unfortunately the knock sensors are piezo elements and don't have a resistance spec. But you could at least check for a short to ground by measuring the resistance to ground. Should be very high (OL).

 

[Mike Beauford]

White_LX in Ontario Canada: Thanks for giving me some needed additional info. I will dig into the FSM as recommended. Appreciate the help.

 

[Eyedaho]

I agree with @2001LC and @white_lx that it's most likely a wiring/connection issue. Those are piezoelectric sensors, basically a barbecue lighter, and are not failure prone. I would certainly want to trace and/or replace the wiring before swapping the ECU.

 

[white_lx]

Few more thoughts: Are you able to clear the code? Or does it come back right away? If its is really intermittent, I would start by inspecting/cleaning the contacts of that connector at the rear of the engine and possibly at the ECM.

 

[Mike Beauford]

I was able to clear the code. It stayed off for a month. I did not come back immediately and dropped off briefly while driving yesterday. It did return when I slowed down after getting off of the interstate. Appreciate all the comments. Spent 2 hours reviewing the FSM and some other posts. Will watch it for a while and clean the connectors after it cools down a bit.

 

[white_lx]

I was able to clear the code. It stayed off for a month. I did not come back immediately and dropped off briefly while driving yesterday. It did return when I slowed down after getting off of the interstate. Appreciate all the comments. Spent 2 hours reviewing the FSM and some other posts. Will watch it for a while and clean the connectors after it cools down a bit.

That is good indication that the sensors are probably OK. The output of the accelerometers is a very small charge, not a voltage. Even a tiny trace of moisture can leak (a part) of the charge to ground reducing the signal output. Look for chaffed wires, moisture in the connectors, connector pin-fit etc. Good luck.

 

[Mike Beauford]

Thanks again for all the encouragement and advice.