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Knock Signal issue...please help

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Old Sep 23, 2009 | 06:06 PM
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Default Knock Signal issue...please help

I replaced both knock sensors on a sc300 because i was getting a check engine (code 52, 55 knock signal).The car once warm at operating temp. will idle real low(about 200 rpms) then die off.....I reset the ecu and changed the knock sensors,but the problem persist.

Also,when I checked the ecu connection it has 16g audio wires were the knock pins go .....I thought it was odd,because all the other wires on the harness are automotive type

is there some way to run the knock signal direct to the ecu from the knock sensor?
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Old Sep 23, 2009 | 07:19 PM
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Originally Posted by S14eva1

Also,when I checked the ecu connection it has 16g audio wires were the knock pins go .....I thought it was odd,because all the other wires on the harness are automotive type
WTF? Do the wires go anywhere? Back into the harness? Or are they just jumped across or something? That's weird. Only think I can think of is that someone before you either was clueless as to what they were doing and used those wires for something else.... or they had some performance mods and was running those wires through some kind of knock detection (or reduction ) device and then back into the sensor...
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Old Sep 23, 2009 | 07:40 PM
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Those are the stock knock sensor wires. They're shielded and supposed to be that way.
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Old Sep 23, 2009 | 09:43 PM
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Doh. For some reason I thought he meant they had been repinned with audio wire and run elsewhere. Haha.
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Old Sep 23, 2009 | 10:37 PM
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ok I understand....

But im still stomped with this issue guys,the car stalls after is at operating temp.

Can I just run wires direct to ecu pins 49,50(knock signal)....and will the ecu provide enough ground to give a signal or shood I look for another way to grown the wires if necessary?
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Old Sep 24, 2009 | 09:39 AM
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i know there was an issue with the 7mgte's for the 3rd gen supras. alot of the guys would buy this sheilded wire kit from some guy or something and over lay the knock sensors wires all the way to the ECU, make sure you do not crimp the sheilding into the wire. that will mess up your signal. kind of like a 02 sensor. also could have a bad ECU, try tapping on it while its running or moving it around
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