P0330 won't go away.

I have an intermittent P0330 error - knock sensor circuit bank 2.

I have replaced both knock sensors and the knock sensor wire.

I now suspect it's either a problem in the wiring harness or the ECU. I sure hope it's the wiring.

Can anybody tell me how to test the wires in the vehicle harness from the connector that goes to the knock sensor harness back to the ECU. Is there a way to bypass that wire with a fresh one and see if that cures the problem? What color wires am I looking for?

Truck is a '96 T100 3.4. I post here because it's basically the same motor as in a 1st gen, and there's usually nothing but crickets in the t100 forum.

Thanks!

 

@BamaToy1997

 

I would love for BamaToy to chime in with any advice if he's around.

Update: I was able to figure out which wires at the ECU went to the knock sensors. The wire colors in the FSM were wrong, but the positions were right. I tested the wiring harness for continuity from the ECU to the plug that goes to the knock sensor harness. The resistances jumped around a bit at first but usually settled down around 1.3 ohms. That seems pretty good to me. The problem is intermittent, however, so maybe whatever wires are not connecting are only doing it some of the time.

Is there a preferred way to clean these electrical connectors to make sure that the connections at the ECU and at the knock sensor harness are good?

 

I haven't been around much on the forums lately as I am trying to get my business stuff taken care of. I really fell behind on my electrical GB kits and the bearings are stacking up, so I haven't been very chatty as of late. Sorry!

You can find a can of electrical contact cleaner at most all auto parts stores. It really does help. If you have an intermittent issue, those are the hardest to figure out. You can do what we call a "wiggle test" where you have a scan tool connected up, looking at the data stream and have someone go through and wiggle each connector and terminal while looking for a data change. Without a good scan tool you are going to be stuck in a "shotgun" approach trying to resolve an intermittent issue though...

 

Hello!
Sorry about the thread revival, it seems I also have run into the P0330 code (and I just picked up my truck yesterday)
I had a 3 hour drive back and most of it was highway, so I kept clearing the code every time it appeared on the drive, or it drove like complete crap. It came up almost every minute or few unless I was coasting/going downhill.

By the time I reached the city and was doing lower speed drives, the code rarely popped up (but it still popped up a few times)

I've been looking for some sort of a (semi detailed?) write up on how to replace the sensor itself and/or the harness or maybe even test the harness if it's at fault.

To reach the knock sensors, anyone have an idea of what I should take off, and what to watch out for?

I understand I may have to replace a few gaskets from reading online, so I was wondering if anyone would have the exact PN's as well.

I know there's a way to splice the 2 knock sensor wires together as well, can I do that without even reaching at the knock sensors themselves?

 

Yes, you can splice the two wires together right next to the ECU - no need to take things apart. It's not a good long term fix, but it will make it run better for now.

To remove the knock sensors or the harness you need to:

-Drain coolant
-Remove air intake hose
-Remove upper radiator hose from intake (you can leave it attached on the radiator end)
-Detach throttle cables
-Remove throttle body (unplug IACV, TPS, 2 coolant hoses, air hose, and some vac lines first)
-Remove upper and lower intake plenum (lots of little bits attached to these - OBD1 port, ground, vac lines, fuel line, EGR Valve if you have one, etc.)
-Remove driver side spark plug wires and lay them on the passenger side
-Remove the upper timing cover
-Unplug injectors
-Remove the fuel lines from the back of the fuel rail (don't lose the banjo bolt washer/gaskets)
-Move wiring harness out of the way (there is a small sensor wire attached to the back top of the intake manifold)
-Remove the intake manifold

There are obviously a lot of other connections and little odds and ends that have to be done in order to accomplish the above list.

The knock sensors are underneath the intake (pic below).

Once you have it down there, I used an adjustable wrench to remove them. The new wire is self explanatory - just unhook each end replace.

I replaced the gaskets between the intake and the heads. The OEM ones are pricey - like $35 each.

I reused the plenum gaskets and the metal throttle body gasket and have had no problems.

I've dug this far in a couple of times recently, and the last time it took 2.25 hours not counting burping the cooling system after I refilled it. If you haven't been in that deep and don't have all the parts memorized, I would say allow 4-5 hours for the job.

The knock sensor in the photo is the thing on the end of that orange wire. The other one is just across and up from it.

 

You, sir, are awesome.

I have an inspection to get done by this Friday, and I won't have that much time to work on the truck.

Do you by any chance know which 2 wires I'd have to splice together temporarily by the ECM till I can work on it?

I'm fairly decent working with electrical and wiring. I'm also terrified of screwing something up on the engine.

Or any chance you might know the PN for the gaskets I should replace?

If not I might have to give it to a shop, and given it takes 2-3 hours of labour plus coolant, all of which is something I don't want to spend money on.

 

What year is your truck?

What I did for the wire splice was to look in the factory service manual for the ecu wiring diagram. I found the two wires from the knock sensors on there. The first thing I did was to repin those two wires in the plug that goes into the ECU - I swapped their positions. Then I started and drove the truck to see if my error changed from the p0330 to the p0325. This allows me to rule out the possibility that the ECU is bad. The error changed, so I know I have either a bad knock sensor or a bad wire at that point.

If the error changes, repin it back how it was. Then cut both wires maybe 3 inches up from the connector, and splice them both to the wire going into the connector for knock sensor 1, whichever pin that is on your truck. EDIT: got this backwards last night. You want the wire from knock sensor one (the one that still works) to be spliced onto both wires that go into the ECM.

I would tell you the specific pins, but my truck is a T100 and is wired differently than the Tacos. I actually tried to sort this on mine using a Taco wiring diagram at first and then had to go find the T100 version because things weren't matching up.

I think your part # for the intake manifold gaskets is 17177-62060, but I can't be sure without knowing the year of your truck.

Here's a link to where I got mine:

http://www.toyotapartsdeal.com/oem/toyota~gasket~intake~manifold~to~head~no~1~17177-62060.html

 

Thanks for the PN!

I have a 96.

I also found this:http://www.well.com/user/mosk/images/Early_Tacoma_ECUs_v1.pdf
but I can't figure out which pin is for the knock sensors from the codes that are given anyways.
I was looking under the "1996 Tacoma 5VZ-FE 4x4 ECM terminals, Automatic ECU"

I also didn't get a service manual when I bought the truck, and I'm gonna go pick myself up one of these tomorrow to make my life easier.
http://www.canadiantire.ca/en/pdp/haynes-automotive-manual-92076-0259368p.html

I've had some time to go over and research all the things I might have to do and might be a good idea to replace.

Things I'm thinking to replace while I change the knock sensor and harness.. because why the hell not?
Coolant (obviously)
Spark Plugs
Spark Plug cables
Plenum gaskets (upper and lower)
Intake manifold gasket

Does anyone else have any ideas for things I should replace while I do this?
I'd like to get the engine running as smooth as possible!

 

5 speed or auto?

 

Auto.

Edit: I'm picking myself a Haynes manual in the next hour

 

Knock sensor 1 is pin E7-17 and knock sensor 2 is pin E7-16.

Remember that the diagram is of the ports on the ECU, so when you're looking at the plug it will be a mirror image.

 

Wow, I can't believe I missed that.



I really appreciate the help by the way, I'm gonna see if I can work a little write up of the procedure.

 

See my edit above about splicing the wires. I got something turned around even though I warned not to get turned around.

 

Ok, well I've now join the knock sensors club after zero issues for 500,000 miles.
I have the p0330 code and need to do an inspection in a week, so I need to be able
to drive the truck and pass before I look into tearing it apart.
I need some help as I don't understand the pin location for the knock sensor
for my truck, 1997 Tacoma, 4x4, v6, standard trans.
I see for the automatic its E7, 16 and 17,
From what I see on the screen shot it says the standard trans is E7, 6 and 30
But there is no PIN number 30, am I missing something??

 

Ok after a few hours on Google I found out that is a typo in the screen shot.
1996 Tacoma which is the same as the 1997 v6, 4x4, standard is
E7, pin 3 and pin 6,

 

It seems you've got it spot on, I got confused myself with pin 30 on the connector as well.

I had my truck inspected recently and it passed like a champ, because I wanted to make sure absolutely everything else would pass as well. I was pretty much expecting it to fail on the engine part.

I cleared the code before I gave it to them, just for the shits and giggles and man it worked, and I still can't fully register that.

I didn't end up doing the splicing fix, and I probably wont till its completely fixed.

So, you do understand which wire you have to splice into which right?

 

I am handy with the wrench, taking the supercharger off is ok, but I'm nervous about having to
take the manifold off, it's the wires and other stuff, because with 500,000 miles I'm afraid
all those wires will break, crack by moving them because they are so brittle. The superchager makes even more heat with the wiring harness right under it and I have had the charger on it since 1998, I was afraid to even move the wires
when I did the rebuild on the charger, I am thinking about the GM swap for the knock sensors because of this. So I need this bandaid first and decide later.
So the code is 0330 = bank 2, that should be pin 3, wire color GR, I guess green or gray,
So that sensor is causing problems,
So bank 1 is ok PIN number 6, wire color B, for black I guess,
So I would cut bank 2 wire, which is pin 3, 3" or 4" back from ECU , gray or green wire. Cap off this wire from the engine side.
Then connect the small cut wire from pin 3, the green or gray wire into the pin 6 wire, black in color.
Does that sound correct??
I could not find any photos of the GM knock sensors swap,
If I had toyota or some repair shop replace the knock sensors and have the wiring harness getting damaged From moving the wires I could end up with some outrageous bill. The harness from Toyota is like 1500.00 alone, and the repair alone for the sensors would be I'm sure 1500 with parts.
So the GM swap is looking as an inexpensive soLotion for me right now, but can't find photos
or the location spot or instructions as of yet, thanks in advance,

 

Thread bump. I know. I'm a horrible person for doing this.

Anyways, I finally, after months got around to tearing apart everything. (It took me like 8 hours because I decided to clean everything well, make sure everything was good, used all hand tools only)

I never ended up doing the quick fix splicing the 2 wires. All I did was keep resetting the code every time it showed up (I kept a scanner in the truck)

There was an immediate, yet not significant power loss every time the CEL showed up, which was quite annoying.

When I finally got to the sensor, I noticed the wire/harness was barely hanging on, cracked up, loose. I'm fairly sure that was the issue.

I ended up changing the sensor anyways, as a just in case measure (at least now I have a possible sensor for backup if the other one fails)

My point is, if you can afford to do everything yourself, start with the harness, see if the problem still persists.
Then go from there. The harness, gaskets and all my parts were relatively cheap for me, as I get a 25% discount with Toyota from my shop.
Even if you decide to change just the gaskets/harness, it'll only be around $100-150.

The truck itself runs muuuuuuch better performance wise, I plan on doing the deckplate mod in the next few days, so that should be fun.

Thank you Tacoma World.

 

So I did get my knock sensors replaced, bought new oem sensors off eBay for 125.00 for the pair. Great deal. Toyota wanted some stupid price for the pair like 250 each or something.
Truck runs great again.