When a knock sensor goes bad, does it trip SES, code 43, AND show false knock?
Thread Starter
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From: NEwhere Ohio
When a knock sensor goes bad, does it trip SES, code 43, AND show false knock?
My service engine soon light has come on. A quick check with my scan tool reveals code 43...Electronic Spark Control Failure. I understand this can be either knock sensors, or the electronic spark control module by the ignition coil. I doubt its the electronic spark control module, because i replaced it last year.
Also...a real-time view of my knock retard on a scan tool indicates up to 3 degrees knock retard every time I accelerate, which would explain why my car feels sluggish.
I have monitored my knock retard before and have never seen knock retard with this setup (long tube headers, hotcam kit, Ed WRight hotcam custom chip). Maybe one time out of 20 I would see 1 degree retard, but never 3 every time I accelerate (lightly even). Before this problem occured, a tapping on the engine block with a tool around the knock sensor verified proper operation of the knock sensors (shown by the scan tool readout).
My main question is: would a malfunctioning knock sensor, tripping the SES light, cause false knock...
Also...a real-time view of my knock retard on a scan tool indicates up to 3 degrees knock retard every time I accelerate, which would explain why my car feels sluggish.
I have monitored my knock retard before and have never seen knock retard with this setup (long tube headers, hotcam kit, Ed WRight hotcam custom chip). Maybe one time out of 20 I would see 1 degree retard, but never 3 every time I accelerate (lightly even). Before this problem occured, a tapping on the engine block with a tool around the knock sensor verified proper operation of the knock sensors (shown by the scan tool readout).
My main question is: would a malfunctioning knock sensor, tripping the SES light, cause false knock...
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Re: When a knock sensor goes bad, does it trip SES, code 43, AND show false knock? (dizwiz24)
I would say "YES" based on the fact I got Code 43 on startup and my knock sensor electrodes were simply caked with grime and oil from a leaking oil pan gasket.
I wiped it off, replaced the pan gasket and cleared the codes. Haven't seen Code 43 since. :thumbs:
I wiped it off, replaced the pan gasket and cleared the codes. Haven't seen Code 43 since. :thumbs:
Burning Brakes
Joined: Aug 2000
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From: Cincinnati OH
Re: When a knock sensor goes bad, does it trip SES, code 43, AND show false knock? (dizwiz24)
My understanding is that if you have a code 43, your ecm will default to predetermined conservative ignition retard values since it can't get proper knock feedback. This may be what you are seeing.
Le Mans Master
Joined: Jun 2002
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From: High Plains Drifter Fayetteville, AR
Re: When a knock sensor goes bad, does it trip SES, code 43, AND show false knock? (Vince Ivanc)
After you go closed loop the ECM sends a signal to the knock sensor, and waits for a reply. If there is no reply it defaults to the pre-programmed tables.
I believe the ESC on my car is mounted near the windshield washer fluid tank on the passenger side. I replaced mine with the updated part# mentioned on 65Z01's site. It made a world of difference in knock detection on my car. YMMV :cheers:
I believe the ESC on my car is mounted near the windshield washer fluid tank on the passenger side. I replaced mine with the updated part# mentioned on 65Z01's site. It made a world of difference in knock detection on my car. YMMV :cheers:
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From: NEwhere Ohio
Re: When a knock sensor goes bad, does it trip SES, code 43, AND show false knock? (JCAIRE2)
JCAIRE,
Thanks for the input. FYI, the 93 uses a removable chip style (old school) computer which does not have the spark control module near the computer.
Some people go to the LT4 knock module which is less sensitive....Mine is all programmed into the chip. And my chip is desensitized for knock slightly due to Ed Wright tuning.
I am betting I am in some type of default, conservative mode.
Thanks for the input. FYI, the 93 uses a removable chip style (old school) computer which does not have the spark control module near the computer.
Some people go to the LT4 knock module which is less sensitive....Mine is all programmed into the chip. And my chip is desensitized for knock slightly due to Ed Wright tuning.
I am betting I am in some type of default, conservative mode.
Le Mans Master
Joined: Jun 2002
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From: High Plains Drifter Fayetteville, AR
Re: When a knock sensor goes bad, does it trip SES, code 43, AND show false knock? (dizwiz24)
Ah, you know, I didn't even think to look and see what year your car was, lol. The stuff I posted is related to L98's. My knowledge of the LT1 is pretty close to zero.
