Knock Sensor headache

[Rock_Rat]

Hey OP, here's the DTC troubleshooting from our manual. Worst case scenario, you can take it into a dealer and have them run it on the scope and check the wave pattern. It'll cost you about 125 for the report.

I also threw in a couple pics of an OEM v. a NAPA brand so you can at least see the OEM style. You say you have OEM, but I'm not sure if you remember what they looked like.

 

[AlecT]

#1) Not your problem - Not correctly torquing knock sensors will NOT throw both codes.

#2) Not your problem - The code is an indication problem not a timing problem. The ECM is not seeing the sensors, thereby throwing the fault codes.

Since it's BOTH sensors then you have a COMMON problem effecting them both.
Possible problems:

• Both "OEM" sensors were not from a reputable source and they look OEM. (You didn't mention where you purchased them)
• The sub-harness is bad. There's three wires in there, black, grey, and orange (I think).
• Did you do a continuity check on the wires? All should read 0.00.
• Is it connected correctly? That was a recent solution on here about a month ago. Check your connector. It might not be snapped in correctly.
• Is it pinched under the manifold. There's a small valley designed for the harness
• Check the harness going from the sub-harness to the ECM for damage going.

This is a start.
Report back. I'm more interested in where you bought your sensors than anything else.

I apologize, I forgot to mention a very important detail. After installing both new knock sensors and wiring harness, I am now only showing the code for knock sensor 1 bank 1. The sensors and harness are OEM Toyota parts purchased from the Toyota dealership.

And yes, the continuity check showed 0.00.

 

[Rock_Rat]

I apologize, I forgot to mention a very important detail. After installing both new knock sensors and wiring harness, I am now only showing the code for knock sensor 1 bank 1. The sensors and harness are OEM Toyota parts purchased from the Toyota dealership.

And yes, the continuity check showed 0.00.

Well I guess you figured this out already but you didn't need to replace the ECM. It was doing it's job and providing you with the CEL and DTC for the sensors. I'm not sure if you can return it or not.

Having just the 0325 code indicates an isolated problem with that circuit. I think you know the possibilities.

Here are my thoughts in priority:

• Bad knock sensor from the factory. Someone may have "returned" a bad one.
• Connectors not properly secured, bent pin?? (knock sensor to sub-harness, sub harness to main harness, main harness to ECM.) That's the only path.
• Possible faulty or broken wire. (Black for bank one)
• Loose knock sensor.

 

[AlecT]

Well I guess you figured this out already but you didn't need to replace the ECM. It was doing it's job and providing you with the CEL and DTC for the sensors. I'm not sure if you can return it or not.

Having just the 0325 code indicates an isolated problem with that circuit. I think you know the possibilities.

Here are my thoughts in priority:

• Bad knock sensor from the factory. Someone may have "returned" a bad one.
• Connectors not properly secured, bent pin?? (knock sensor to sub-harness, sub harness to main harness, main harness to ECM.) That's the only path.
• Possible faulty or broken wire. (Black for bank one)
• Loose knock sensor.

Yeah my guess is your first option as well. I checked through the wires and connnectors throughly. Looks like I’m taking it apart again this weekend. Hopefully I can get some money back. I appreciate all of your help. I’ll post back after I do the job to (hopefully) inform you of the culprit.

 

[fightex]

#1) Not your problem - Not correctly torquing knock sensors will NOT throw both codes.

#2) Not your problem - The code is an indication problem not a timing problem. The ECM is not seeing the sensors, thereby throwing the fault codes.

Since it's BOTH sensors then you have a COMMON problem effecting them both.
Possible problems:

• Both "OEM" sensors were not from a reputable source and they look OEM. (You didn't mention where you purchased them)
• The sub-harness is bad. There's three wires in there, black, grey, and orange (I think).
• Did you do a continuity check on the wires? All should read 0.00.
• Is it connected correctly? That was a recent solution on here about a month ago. Check your connector. It might not be snapped in correctly.
• Is it pinched under the manifold. There's a small valley designed for the harness
• Check the harness going from the sub-harness to the ECM for damage going.

This is a start.
Report back. I'm more interested in where you bought your sensors than anything else.

[MENTION=116467]Rock_Rat[/MENTION], my 97 Limited is throwing p0330 after the manual swap. I found the 3 wires to the sub assembly, presumably 1 to each knock sensor, where does the 3rd one go? Is it a ground? Thanks.

 

[redheadmetaldiva]

[MENTION=116467]Rock_Rat[/MENTION], my 97 Limited is throwing p0330 after the manual swap. I found the 3 wires to the sub assembly, presumably 1 to each knock sensor, where does the 3rd one go? Is it a ground? Thanks.

I replaced my knock sensors a few months back - the wiring goes back in the way it came out - one plug to each sensor - the third plug goes back in and connects back to the other end of the plug. Somewhere near the left hand side of the timing belt cover if I recall correctly.