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Discussion Starter · #1 ·
my 94 626 ES (v6) is throwing a code 5...knock sensor.

so i went to haynes and tried to test it. The manual says that at 68 F the ks should have a resistance of 560ohms. If its way out of spec replace it (PITA)

set my multimeter to 2000 ohms and tried to read it...i get no reaction (reading =1 which means infinate resistance. I tried at all ohm settings...all the way from a range of 2000Kohms to a range of 200 ohms and not a peep.

even tried to take a reading in the wires in case the connector was bad (poke a hole in it using the poker). nothing...same story on my mx6 (which is not throwing a code)

anybody want to do me a huge favor and take some resistance readings on their knock sensor (its as easy as unplugging it and sticking the electrodes in)

i gotta be doing something wrong
 

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You're not doing anything wrong, I tried the same thing about 2 months ago and got nothing. So I went to the scrapyard and tried it on about 10 different probe/mx6/626's and got nothing on any of them. Either the test doesn't work as it's supposed to, or knock sensors are failing all over the place.
 

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where are you measuring from? from what i recall theres one wire and a shield so you had to measure from one pin to ground (not across both pins) but i may be wrong.
 
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Discussion Starter · #4 · (Edited)
You're not doing anything wrong, I tried the same thing about 2 months ago and got nothing. So I went to the scrapyard and tried it on about 10 different probe/mx6/626's and got nothing on any of them. Either the test doesn't work as it's supposed to, or knock sensors are failing all over the place.
thanks rene (can't karma you)...the car has the code on as soon as it gets close to op temp so its running in safe mode all the time with the retarded timing=bad mileage...so i want to fix the problem some how or another....the thing is the car runs fine. Although it did have a valve job done on it (before i bought it) maybe somethings actually making noise in there that would cause the knock sensor to go off...i know our valve train is quite noisy but that seems pretty unlikely


where are you measuring from? from what i recall theres one wire and a shield so you had to measure from one pin to ground (not across both pins) but i may be wrong.
haynes says measure between terminal A (picture points to one of the wires in the connector) and ground.

i'm assuming that the red wire would be terminal A and that the black would be ground. I also tried using the ground on the battery...:shrug:

i tried poking all over the place... with no results
 

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I'm not sure if this is any help: 1993-1995 Engine Controller Malfunction Codes Try measuring the voltage across the wires (probe into them) with the engine running.

I thought that (some) knock sensors had a coaxial wire (one wire inside a second wire?

I remember reading (on ProbeTalk I think) that early V6 Probes/MX6s/626s had a cover over the knock sensor, but it was removed on later models, because they found that the cover sometimes caused a reverberation which falsely indicated knocking. If there's a protective cover on yours, you should remove it.

There's a thread somewhere (Mazda626net I think) which explains how to remove the knock sensor without removing the IM (not easy, but possible!).

And that about sums up my knowledge of knock sensors.
 
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