GT40 3854216 12-h-v

[jhersey29]

What is this part for and what does it do? It has 4 wires going into it. 2 black, a blue and a yellow. It is located behind the ECM. 3854216 12-h-v Mexico is listed on it.
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[jhersey29]

Part number 98 in the below link

This sure looks like the G40 wiring harnass http://www.crowleymarine.com/johnson...arts/42188.cfm

Looks like this http://www.ebay.de/itm/OMC-Knock-Mod...-/231225634642

[jhersey29]

Bump, no one knows what this thing is for? It's not in the service manual.
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[aZ`]

GT40 3854216 12-h-v

A knock module can be used to retard timing using a knock sensor. "Knocking" or "pinging" is pre ignition of your combustion mix and isn't good for your motor. Most ecu's these days have software to drive a knock sensors. But if you have an older ecu or even a carby then a knock box (knock module) can manually pull some timing if a knock is detected.

Does one (or more) of the wires run down to a sensor that is screwed into the block?


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[jhersey29]

The wires disappear into a bunch wrapped inside a sleeve. The color does not match the wire on the knock sensor. The engine does have a knock sensor.

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[jhersey29]

Correction, yes the knock sensor black with green stripe feeds into it. Was hard to see the get wen stripe but pulled back some of the protective housing. This part then goes to the ECM?
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[aZ`]

I am not all that familiar with this ECM. It could possibly go to the ECM as basic input and then the ECM May retard ignition or it may go to the ignition module or be wired to the distributor itself.


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[jhersey29]

Found it in the manual under the knock sensor. It is very briefly mentioned and not listed in the parts section. It amplifies the signal from the knock sensor and sends it to the ECM.
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