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01 knock sensor harness woes

Discussion in '1st Gen Tundras (2000-2006)' started by jmtaylor138, Mar 6, 2025.

  1. Mar 6, 2025 at 5:25 PM
    #1
    jmtaylor138

    jmtaylor138 [OP] New Member

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    2001 4.7 AC 4wd limited. 225k on the clock.

    So the critters got me. Chewed my bank 1 connector. Not a fun time taking the intake manifold off, but pretty straightforward. Got a knock sensor harness from rock auto, and I could not find where to plug the three prong connector in. Seems like other people have had this same problem, and plenty of folks have soldered in a new connection and that was that.

    So I did just that, heat shrink, elec tape, I've done plenty of soldering. The last few inches are not shielded. I made the connection an inch away from the plug.

    Button everything back up, take her for a spin....same problem. po325. Truck loses a little bit of giddy up just like before. Runs strong until it pops on. I can clear it on the fly with the scanner, and the truck runs great with the code off.

    I order another intake gasket in case I have to get back in there. While I waited, I cleaned the TB, installed a new PCV valve just in case the knock was real (which would be a serious coincidence.) No change, plugs have maybe 1500 miles on them, and I cleaned the maf about 3k ago.
    I get the intake, open her back up to check continuity. Now I can't seem to make sense of what the manual is trying to tell me.
    So with the e7 plug disconnected, and both knock sensor plugs disconnected. I am not getting continuity from the bank 1 connector to e7 23 or e7 22, but I am getting it from bank 2 to e7 23 (black wire) which is supposed to be bank 1. I'm not really sure what to do next. My solder job looks fine and passed the tug test. The rest of the loom doesn't look disturbed. I did find a plug with some weird stuff going on behind the manifold, that I may have messed with, that I can't identify. I doubt its related. Probably something wacky the PO did installing secret kill switches, remote start or some weird horn jumped to a injector wire I found and ripped out. I've put 125k on this truck over 5 years without issue though. Some help IDing that plug would be helpful as well. thanks in advance

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  2. Mar 6, 2025 at 5:27 PM
    #2
    jmtaylor138

    jmtaylor138 [OP] New Member

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  3. Mar 6, 2025 at 6:03 PM
    #3
    BubbaW

    BubbaW Blessed 2 B above Ground

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    T150 Lover
    According to the 3rd picture you posted, that's from a 2003 Diagnostics and refers to a 5VZ ENG and your Tundra is a 2001 4.7 2UZ, big difference electrically. You need to be checking e7 17 and e7 18 for your continuity checks as noted in the below pics from a 2001 EWD.

    Also, thanks to @RainMan_PNW , all 1st Gen Tundra electrical wiring diagrams can be found at this link....Ultimate TUNDRA Wiring Diagrams Collection | Toyota Tundra Forum

    2001 Knock Sensor.jpg

    from 2001 2UZ Diagnostics....

    2001 Knock.jpg
     
    RainMan_PNW and KNABORES like this.
  4. Mar 6, 2025 at 6:53 PM
    #4
    jmtaylor138

    jmtaylor138 [OP] New Member

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    whoa! thank you! Looks like the funny chewed up connector behind the starter is EC1, and the knock sensor wires pass through that. Am I reading this right? what are the chances the same wire was chewed up in two places?

    edit: continuity test confirmed those are the wires! Mind=blown, he had so many wires to choose from!
     
    Last edited: Mar 6, 2025
  5. Mar 6, 2025 at 7:06 PM
    #5
    shifty`

    shifty` I'm having daydreams about night things

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    (see signature for truck info)
    Only a note, don't want to jump in Bubba's way, he's way better at electrical than me.

    Be very careful when looking in FSM and at the EWD, that you note at the top of the page exactly what engine AND what year you're dealing with, since there's subtle differences year to year on the stupidest stuff possible. If you have the V8, it's 2UZ.

    -- Signed, fellow periodic knock code sufferer (P0328 here)

    upload_2025-3-6_22-5-28.png

    upload_2025-3-6_22-6-39.png
     
  6. Mar 7, 2025 at 5:17 AM
    #6
    BubbaW

    BubbaW Blessed 2 B above Ground

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    T150 Lover
    Hard to tell from the below pic but if it is a 6 pin connector and matches the colors shown in below EWD schematic, it is indeed EC1. It is for a 4WD and EC2 is only a 3 pin connector for 2WD. The EC1 also services the ADD of 4WD.

    2001 EC1.jpg

    2001 Knock and ADD.jpg
     
    shifty` likes this.
  7. Mar 7, 2025 at 4:46 PM
    #7
    jmtaylor138

    jmtaylor138 [OP] New Member

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    yes, I got the ec1 all tidied up this morning. Truck is running great, no code. I still can't believe the same wire was chewed in two different places so far apart, when he had so many others to choose from, but that's exactly what happened!
     
    w666, shifty` and BubbaW like this.

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