how much voltage is suppose to be on the knock sensor wire on a 1991 4.3,is it ac or dc?and when is it there.
how much voltage is suppose to be on the knock sensor wire on a 1991 4.3,is it ac or dc?and when is it there.
with a knock sensor connected, you should see around 2.5 volts.
disconnected, around 5.0.
it is a DC signal, if you look at the signal on a scope, should look somewhat like a sine wave, just not with a very high amplitude(unless knock is occuring).
1995 Chevrolet Monte Carlo LS 3100 + 4T60E
May I ask why your looking for this info? Do you have codes? Do you have a scope? Is the engine you have the sensor on have any internal mods?
no mods, last few days had continus knock counts no running or mechanical failers I can find. 670 counts in 15 miles I am suspecting a ecm starting to fail? it is a standard trans and been peacied togather its got a 3.9 ohm I was thinking it might need a 8.1 knock sensor.
Electronic Spark Control (ESC) Module Wiring
Electronic Spark Control (ESC) Module Wiring
I have 9.2 volts on the sensor plug. my other meter shows 9.2 milli volts
Last edited by ony; 10-14-2014 at 08:55 PM.
this has 2sensors one in the back of the passigr side head 1 in the drivers side that goes into the coolent chanmber. hi got ruck I put a 4000 ohm sensor in the right side head and left the left side un hooked it worked pretty good for 8 years. then last week k//////////////////// to heaven. I run the wire over to the left side while ago to the 8000 omh no knock ,only when it is shut down then I get 7-13. I cannot hear it but may be I got a bad wrist pin. [end of story the sensor screwed into metel alone picking up lots of knocks,sensor screwed into a water jacket only picks up knocks whenthe engine is shut down?]
I think you're reading one of those two DMMs wrong, there is no way one of them will be off by exactly two magnitudes from the other.
I know some DMMs display things a little odd, as in where it puts the decimal, or where might appear a decimal, can cause it seem wrong.
Grab the DMMs, and connect them to the battery, use the one that reads as close to 12V to read the knock sensor wire, then let us know what it says. :)
The man who says something is impossible, is usually interrupted by the man doing it.
do you hear or just see knock
Last edited by suffolkauto01; 10-15-2014 at 05:05 AM.
when I get to work I will try another volt meter,i have tried 3 thy all read different they are really cheap meters used to check charging volts mostly. I don't hear any knocks at all I don't hear very well but uselly if I lug the truck done real low I can hear if it spark knocks .I mostly see them at hy speed with tp and my snapon scanner.
Last edited by ony; 10-15-2014 at 01:16 PM.
again check esm wiring
I borrowed a flucke meter it reads 0 volts with key on engine off, .005 with the engine running and the sensor unplugged.
005 is ground make sure u hit range so 0.00 and your on dc is it a fluke 88 again i think your in the wrong area i seen this a lot and it was the esm are you getting code 43 don't test between 2 wires check the power wire using batter ground and also check the ground wire using battery ground at ground should be below or .030 on v/dc if higher bad ground Check for 2.5 dc volts on the knock sensor circuit, key on engine off (KOEO), with the knock sensor plugged in. If the voltage is over 3 volts, f
Last edited by suffolkauto01; 10-15-2014 at 06:34 PM.
what is exact car
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