Knock Sensor
 

I keep getting a code 44 every so often, code 44 is knock not detected, I replaced the sensor last year, is it common for these to go bad often? Any idea where to get the connector? it is a push in connctor that is specific to the sensor, I want to try and replace that in case it's corroded,

Thanks

more or less stock, 502 mpi, reprogrammed ecm and gil exhaust, that's it.

Is the code 44 for knock "NOT" detected or "KNOCK DETECTED".

If it keeps coming up then you might have a problem with the inside of the ECM as well. And also X2 on what Rage is asking. Also what octane of fuel do you run 87,89,91

43 is knock detected, I have never had a 43 alarm and I have ran it with the rinda tool atttached where it says no knock detected. The alarm only goes off every so oftem so it seems like a short somewhere.

i use 87

This is a little difficult to follow. Please clarify

Sorry, didnt see your response.
I have a 2000 502mpi/ Mefi3

I am getting a code 44, which is "knock not detected",

Yesterday it happened, after about 15 miles into a 22 mile run, 1-2 chop conditions, running about 4K rpm. The boat started to run poorly after that, I didnt push it and limped to my destination.

I cleared the code and on my trip home, got the alarm again, I ran about 3K rpm on the way home in about 2-3' seas.

The ecm has been reprogrammed if that matters,

does the timing automatically retard if this code is present?

I took off the sensor and hooked it up to an multimeter and I get 3.85 ohms (I think I am measuring ohms), when I tap on it with a screwdriver I can get it up to 4.5 ohms, not sure if that means it is working.

what the hell does "knock NOT detected" even mean ? i would think that's a GOOD thing... why should it hate that ? and yes... when people are screwing around with the ecm code it is not uncommon for all the alarms and triggers to be hopelessly screwed up. if the knock sensor is triggered, you get a " knock event detected" log entry and it kicks the timing back until it goes away and then gradually works it back up... it would never ever occur to me to "tune" or program an ecu unless i had a box stock spare one to use as a test piece for times like this.

"Not Detected"
 

I know you said you replaced the part.. Sounds like the ecm is not getting a reply from the inquiry to the sensor. Perhaps the sensor has failed and it's telling you that. Or there is a bad connection and it won't act right until it has the correct sensor voltage. The quickest way but not cheapest is to get it from a dealer obviously - Regarding the push in connector.

Although, depends on who did your program etc... I've seen some weird stuff with that.

so you think it isn't detecting the KS at all ? could be ... a scanner in real time would show that.

Does this 502 MPI ECU have something like a "Guardian Mode" as does the Merc 496 PCM555 ECU?

My post was assuming that you had "seen" the "not detected" from within the scan tool. If not connected, or bad connection etc... it will tell you somehow either way.

Don't forget that scanners often fool you or just point you in the right direction.

Good luck.

from what I understand the ecm looks for a signal from the sensor and it cant get one so it alarms, I dont know if it retards the timing at that point or not, I wasnt in a place to pull out the scan tool. it did start running like crap after the alarm went off so it felt like maybe the timing was retarded.

I will replace the sensor and try and find a connector at a GM dealer, Merc only sells the harness complete.

I bought the boat with the ecm reprogrammed but I agree, I wouldnt mess with it again, not sure what I gained except I can run 5100 or 5150 without hitting the rev limiter.

Thanks