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I have a '98 4Runner, 5VZ that I recently turbo'd, I have been getting a p0325 knock sensor code that just won't go away. I have a brand new OEM KS harness, I have de-pinned and swapped pins at the timing cover connector (EB1) and the codes swapped to the P0330 so it makes me think I have a wiring issue.

I decided to make a temporary GM KS mount/conversion to see what happened. Still pick up the P0325. So, OEM sensors and harness are bypassed. I OHM'd both gray and black KS wires back to the ECM, they tested good. I OHM'd my home made harness to the GM sensors (good). I tested the GM sensors for resistance and AC voltage (good). I am at my wits end and out of ideas at this point. Looking for help/suggestions!

Thanks!
 

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Mambeau / Admin
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Let's back up ...

Is there anything particular that happens before the P0325 code gets thrown? Is the CEL 'on' from the beginning, or does it appear after something?
 

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Let's back up ...

Is there anything particular that happens before the P0325 code gets thrown? Is the CEL 'on' from the beginning, or does it appear after something?
I have been thinking about the same thing. Before going turbo I hadn't had an issue. The only thing that comes to mind is when I wired up my FIC6. Which, I have inspected the wires over and over. Nothing is tapped into the KS wires, they aren't nicked. The only thing I can think of is maybe noise interference? But, I don't get a P0330 (opposing bank) code and the wires are right next to each other. I have also noticed I never get the code at idle or at low (neighborhood) speeds, I rarely get it around 40 MPH and I ALWAYS get it on the freeway around 60MPH.
 

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if the code changes when you re-pin the terminals, then the problem (open/short or looseness) is somewhere between the EB1 connector and the knock sensors and not with the ECU . Now having tested and even bypassed this area with the GM sensor conversion and still having the problem occur, I can feel your frustration...but there has to be something wrong in that area.
Can you Tee the two circuits off the one good sensor circuit at the EB1 connector temporarily just to eliminate that code and see if anything else pops up?


Good luck and hope you figure it out soon. Hate when issues like this come up that prevent you from enjoying your toy
 

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Discussion Starter #5
if the code changes when you re-pin the terminals, then the problem (open/short or looseness) is somewhere between the EB1 connector and the knock sensors and not with the ECU . Now having tested and even bypassed this area with the GM sensor conversion and still having the problem occur, I can feel your frustration...but there has to be something wrong in that area.
Can you Tee the two circuits off the one good sensor circuit at the EB1 connector temporarily just to eliminate that code and see if anything else pops up?


Good luck and hope you figure it out soon. Hate when issues like this come up that prevent you from enjoying your toy

I agree that I can rule out the ECM because I can get the code to swap banks with re-pinning. Typing out my whole issue from beginning to current will probably be super confusing to read but I am going to attempt to document it.

First I want to clear up that I have factory knock sensors in the valley.
I have a less then 6 month old OEM KS harness.
The GM sensors are mocked up on a small piece of plate steel simply bolted to the intake manifold (temporary diag purposes) right by the EB1 connector.

I first started noticing the knock code after turbo and FIC6 install. KS wires were NOT tapped, no visible damage seen.
The code was a frequent P0325 bank 2 passenger side.
Sometimes I could go a full day without it turning on and other days it would turn on immediately after erasing it.

I started with the following:
-Swapped KS 1 and 2 wires (black and gray) at the EB1 connector, code jumped to P0330. Sensor suspected.
-I wired in a little jumper wire between black and gray on the KS harness after EB1 before the shielding, code didn't show up for a few days but then P0325 and P0330 popped up..
-Purchased 2 GM SU1075 KS's and made the temporary mount.
-I then wired up the GM sensors to the EB1 connector eliminating the OEM KS harness and OEM sensors.
-P0325 popped back up... *sigh*

Getting the same code with the factory harness and sensors bypassed really through me off...

-I re-inspected my FIC install, nothing abnormal noticed.
-I OHM'd the black and gray KS wires from the ECM connector to EB1 (tested good).
-I OHM'd my home made harness for the EB1 to GM (good).
-I OHM'd the GM sensors (good).
-Tested the AC voltage output from the GM sensors (voltage was being produced when tapping next to the sensors).
-Swapped the connecting wires on the GM sensors and the code went to a P0330... :shrug: Bad new GM sensor?!

Where it may get confusing... As of last night (1/09/19)

Since the main code was the P0325 (black wire, passenger side) I ran the suspected GOOD GM sensor on the bank 2 (black wire to ECM) and wired the bank 1 (gray wire) to the factory bank one KS that I have NOT had issues with (suspected good). I drove to work this morning and got a P0330... So now all the sudden the OEM "suspected good" sensor is giving me trouble?! ugh

So, my next idea is to make a little 2 to 1 harness to go from both black and gray EB1 wires to the 1 suspected good GM sensor. Then if I still get a code(s) I will move that 1 wire over to the other GM sensor (previously suspected bad) and see what happens...
 
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