PCM ex 343 2011 knock sensor code???

FLeboeufFLeboeuf Posts: 87 Baller
Hi ballers!

I have been having the same knock sensor code popping up every now and then since the beginning of the season on my Nautique 200. Its always the port side sensor and its the DTC 327 code which means the sensor detects less than a certain amount of volts. The dealer mechanic came twice. The first time he realized I put thread scellant which I learned is a big NO. He cleaned it a bit, put some grease and put it back and it worked for about a month. The codes came back. The check engine light turned on when going over 34 mph. This time the cam retard was off a couple of degrees and the rotor was not installed properly. That worked for another two weeks. The codes popped up again. This time I took off the left sensor and cleaned the threads in the block and of the sensor. It was very dirty. It worked another two weeks until today. This time the check engine light always comes on when Im going about 30 mph with or without zero off. The check engine light turns on only about an hour at least after start up. It never lights at 36 mph and never under 30 mph.
The mecanic says the wires are good and the sensor works. That Im sure because I ve tested the sensor and it does work. Mecanic is thinkg maybe the cam retard was not ajusted properly...
Has anyone experienced this and what did you do to solve that problem? It would be nice to avoid having the mecanic come back. It is starting to get expensive..




  • FLeboeufFLeboeuf Posts: 87 Baller
    Oh yeah I forgot, engine runs well, temp., Oil pressure everything is normal and I dont hear any knocking.
  • Jody_SealJody_Seal Posts: 4,055 Mega Baller
    Scanning the engine with diacom will identify cam offset. Hopefully the knock sensor thred does not have Teflon tape on it or some other thred sealer other then the patch lock that comes on the unit.
    Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise.

  • gmutgmut Posts: 234 Baller
    @FLeboeuf did you ever fix your knock sensor problem? I am having a similar issue. 3300 rpm and above check engine light comes on and display reads knock sensor see dealer. The boat runs just fine other than the check engine light coming on.
  • FLeboeufFLeboeuf Posts: 87 Baller
    edited July 2020
    @gmut, Yes I did. I think I changed both knock sensor. Did the same again last year. I changed only one. you need to be careful with a new ones, if you drop it it can become faulty. If you don't have the diacom software, change them both, it might be cheaper than having a mechanic plug his computer and changing a part that is simply screwed in the block like any regular bolt.
    If you have the diacom, it will tell you knock sensor 1 or 2 (if you have the same engine as mine). to know which is whcih you just unplug one and run the boat then unplug the other and run again and you will be able to figure out which is where. very simple fix and yes the boat runs fine even with the light on.
  • oldboyoldboy Posts: 1
    I know this is a old thread, but a bit of usefull info.
    on the EX343 5.7ltr, knock sensor fault in this particular failure mode only !!!
    3100 - 3300 RPM, 32 - 35 mph, light load

    knock sensor fault in any other situation does not apply

    FMI 4 open circuit, i.e. the knock sensor is registering low return voltage
    usually one knock sensor only
    the PCM software on this engine in this particular mode above believes the knock sensor return voltage is too low (less than 0.050 - 0.070 on the diagnostics)
    when you accelerate to above this rev range the knock sensor volts go up to 0.100 and above and no fault code is set, I believe (could be wrong) the ECU does not look at the knock volts below 3000RPM

    replacing knock sensors you could possibly fluke onto a set up that registers slightly higher return voltage and the problem goes away - great
    but if this is a reoccurring problem and the knock sensors are known to be good (i.e. are new)

    I have found a solution
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