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Old 02-20-2011, 02:40 PM   #1
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Default FM Link ECU Knock Sensor Problem

I bought my car a year ago with the Link already installed and have just gotten around to datalogging. I was horrified to find I had no knock signal showing in the logs. The display when checked shows a zero level of knock at all times. The wiring from the knock sensor to the ECU tests okay with an ohmeter. I took the knock sensor off the motor mount, connected it to the ecu and tried tapping on it - still 0 levels on the display. I tried connecting an audio source, an mp3 player, directly to the RCA jack on the ECU and still the display reads 0. It seems as if the knock circuit in the ECU is hooped. What is the next step? I guess I can open up the ECU and look for something obvious like a broken wire. Any other suggestions?

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Old 02-20-2011, 02:44 PM   #2
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When you get it corrected, move the knock sensor to one of the other, more forward tapped holes in the block and put the correct screw in the motor mount. The Link knock sensor engages only a couple of threads in the few applications I have seen and can strip out easily when in the motor mount screw hole.
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Old 02-21-2011, 09:40 AM   #3
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It's the same bosch sensor that was used on a gazillion GMs/saabs. I picked up a spare at the pullapart for $2... or eBay for $10 delivered:
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Old 04-05-2011, 11:06 PM   #4
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did you ever find the problem with your knock sensor
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