mooncricket

For the last week or so I've been getting the Service Engine Soon light when cold on my 92 LT1, but it usually goes off very shortly after coming on... checked codes, have Code 43. Since my ECM is only a few months old, I'm thinking to go right to the Knock Sensor.

I also have a loose exhaust tin that rattles around a bit... could this be the culprit instead of the sensor itself? I just don't know how sensitive the knock sensor really is.

Any other thoughts from other 92 owners who've had this code?

Also, exactly where is the knock sensor located on these?

65Z01

If the voltage seen by the ECM on the line from the knock sensor goes above 3.5Vdc (open circuit) or below 1.5Vdc (short) the code will be sent.

You can check for a short at the knock sensor but need to probe the dk bly/wht wire at pin GF9 to test for the open condition.

mooncricket

So where is Pin GF9 on this? I don't have a book for this one.

ittlfly

65ZO1 is correct. However, if part of your exhaust is loose and knocking around it MAY be picked up by the sensor and as a knock and setting the code.
You have 2 knock sensors (one on each side of the block) about mid point and just above the pan. They are each covered by a tin shield which is held on by 2 7/16 nuts. The "pin GF9' is located at the back of your ECM. It is 1 of many and you need a manual (like Helms) to help you locate it on the back of the ECM. Has anyone removed / replaced the knock sensors recently? If so, they need to be torqued at 14 ft. lbs. If they are over torqued they can send a false signal. Hope this helps.

SPD DMN

I usually just replace the knock sensors when I get a 43. Make sure to torque them between 10-14ft lb. Like ittlfly says, overtorqing them will cause premature failure and a code 43.