Knock Sensor Wiring Harness? Please Help!

[mwaters1]

My 97 ES 300 is throwing knock sensor codes 0325 and 0330 with CEL. From the posts I've read on CL, this may be caused by faulty wiring harness exposed to heat over time. So rather than tackle a big job to replace sensors, or paying big bucks to dealer, I figured I'd try to replace the harness ($27 from Lexus dealer). So, I bought part # 82219-07010 but can't seem to figure out where it goes. Lexus gave me a diagram but I can't find corresponding wire. What am I missing? Do I have to take off the manifold to get to it? (ugh!) Thanks for any help!

[lenore]

Yup, the manifold has to come off...and you still may have bad knock sensor....

[lexis lexus]

Agree, have to take the manifold all the way off to replace the wiring harness, and while there might as well replace the sensors as well as the spark plugs, head gaskets if they're leaking (overheating?), and do the timing belt if it's been there for 100K or more -- and anything else you happen to break along the way.

Pulling off the intake/manifold takes about 3 hours for me now, but initially took a good 8 hours as I'd never been there before. But it's not impossible, if you like to wrench and have a Haynes manual.

Let us know if you want to try it and advice will be there.

Someone suggested it is possible to disconnect the old harness (the connector is on the driver's side of the rear bank of cylinders under the throttle body)and connect up the new harness to an externally mounted knock sensor. But I tried this and it didn't work.

When I finally got down to the wiring harness, I discovered that the same heat that cooked the harness and also destroyed the knock sensors as well. (crumbling...)

LL

[DEATH_AWAITS_YOU]

My 97 ES 300 is throwing knock sensor codes 0325 and 0330 with CEL.

Codes P0325 and P0330 refers to both knock sensors under the intake on each cylinder head. It is unlikely that both have failed at the same time. The harness you are referring to is the sub-harness that goes to both sensors and comes out at the back of the intake. Good chance this is all you need as the most likely culprit would be that rodents ate your harness(seen it a hundred times). Look at the back of and underneath the intake(as much as possible) and look for rodent activity, wire harness damage. Don't ask me why, but they seem to love to go under the intake manifold and chew on wires!

[mwaters1]

Thanks for the input. I decided to give it a try....it was ONLY 100 degrees in Dallas today and it took me about 8 hours. It was a tedious job, though everything seemingly came together at the end...HOWEVER, when I went to start the car, expecting success, it wouldn't start! It cranks, sounds like it wants to start for a couple seconds, then just keeps cranking. I scanned for codes and got a P1300 (Igniter Circuit Malfunction (Bank 1 Or No. 1)). YIKES! I may have more trouble now than before I tackled the knock sensors. At least I could drive it before, but now I'm without wheels. Any ideas? Thank you!

[lenore]

Go back over your work, you may have left a harness unplugged....

[mwaters1]

Yep, you were right lenore...igniter was unplugged...but now rough idle and stalling @ low rpms. thanks bro!