Code 43 and a dumb question
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 1,123
Likes: 1
From: Rockland County NY
Code 43 and a dumb question
i just pulled a Code 43 from my 91 Coupe. According to the "Ultimate C4 DIY thread" it's an Electronic Spark Control problem. Is this just a sensor that can be replaced?
Racer
Joined: Apr 2011
Posts: 296
Likes: 1
From: Tipp City Ohio
ESC is a module involved in the knock sensor circuit. It will, along with the knock sensor itself, retard the timing if it senses engine knock. Code 43 could be pulling if the ESC module or the knock sensor is going bad, or a ground is intermittent. On my 88, the ESC is on the passenger side on the firewall behind the tire. Not sure for the 91.
Racer
Joined: Apr 2011
Posts: 296
Likes: 1
From: Tipp City Ohio
I can tell you that if the knock sensor or ESC is disconnected, it could throw that code. Double check the connections. I'd also clear the codes by disconnecting the battery then see if the code throws again.
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 1,123
Likes: 1
From: Rockland County NY
is the knock sensor part of the electronic control unit that the chip is located in?
Race Director
Joined: Jun 1999
Posts: 14,924
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From: Merritt Ils Fl
Racer
Joined: Apr 2011
Posts: 296
Likes: 1
From: Tipp City Ohio
Yes, the knock sensor is in the block listening for abruptions. That is wired to ESC, most likely mounted on firewall near blower motor (passenger side). ESC has like 5 wires coming in, it is shaped and sized little like a large pack of matches. Of the wires, one is from knock sensor, one is ground, other 3 go to ECM to send the signals for the knock pulse so the ECM can decide to retard the timing if needed to compensate for the knock.
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Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 1,123
Likes: 1
From: Rockland County NY
Yes, the knock sensor is in the block listening for abruptions. That is wired to ESC, most likely mounted on firewall near blower motor (passenger side). ESC has like 5 wires coming in, it is shaped and sized little like a large pack of matches. Of the wires, one is from knock sensor, one is ground, other 3 go to ECM to send the signals for the knock pulse so the ECM can decide to retard the timing if needed to compensate for the knock.
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 1,123
Likes: 1
From: Rockland County NY
i just finished replacing the sensor and found a wierd thing. When I unscrewed the unit from the block, I was expecting to lose some antifreeze, but nothing came out. WTF? I got my flashlight and looked into the hole and it was solid as a rock. I took a screwdriver and poked at it and finally broke through the sediment and took the antifreeze bath I was expecting earlier. I'm thinking that somewhere along the line, someone must have poured some of that radiator stop leak stuff in and it solidified in the knock sensor passage. I wonder if it's doing that in other places as well?
By the way, I disconnected the battery to clear the codes, took it for a spin and it's running great once again!
By the way, I disconnected the battery to clear the codes, took it for a spin and it's running great once again!
Racer
Joined: Apr 2011
Posts: 296
Likes: 1
From: Tipp City Ohio
i just finished replacing the sensor and found a wierd thing. When I unscrewed the unit from the block, I was expecting to lose some antifreeze, but nothing came out. WTF? I got my flashlight and looked into the hole and it was solid as a rock. I took a screwdriver and poked at it and finally broke through the sediment and took the antifreeze bath I was expecting earlier. I'm thinking that somewhere along the line, someone must have poured some of that radiator stop leak stuff in and it solidified in the knock sensor passage. I wonder if it's doing that in other places as well?
By the way, I disconnected the battery to clear the codes, took it for a spin and it's running great once again!
By the way, I disconnected the battery to clear the codes, took it for a spin and it's running great once again!
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 1,123
Likes: 1
From: Rockland County NY
So much for the happy ending...it studdered again on the way to work this morning 
No SeS light went on this time. I have a buddy with a real OBD1 scanner... I went old school and used a paper clip. Maybe the scanner will tell me something that the paper clip couldn't. I wonder if there's a big difference between an aftermarket knock sensor and a GM one? I used an aftermarket unit.
No SeS light went on this time. I have a buddy with a real OBD1 scanner... I went old school and used a paper clip. Maybe the scanner will tell me something that the paper clip couldn't. I wonder if there's a big difference between an aftermarket knock sensor and a GM one? I used an aftermarket unit.
Pro
Joined: Jan 2007
Posts: 584
Likes: 2
From: Gilroy Ca.
Don't rule out the possibility that everything is working correct and the knock sensor is hearing a knock, possibly detonation. If you just had it chipped(tuned), maybe the advance is high enough to cause a ping or you have bad gas. This is not a good thing to guess at if you drive it hard. You could be running lean( cause knock), too much advance(cuase knock), poor fuel(cause knock)or the failure of your safety warning devices. I would first assume the sensors are working and work from there, and don't ignore a warning for very long. It is there to save your motor. Good luck.
Racer
Joined: Apr 2011
Posts: 296
Likes: 1
From: Tipp City Ohio
So much for the happy ending...it studdered again on the way to work this morning No SeS light went on this time. I have a buddy with a real OBD1 scanner... I went old school and used a paper clip. Maybe the scanner will tell me something that the paper clip couldn't. I wonder if there's a big difference between an aftermarket knock sensor and a GM one? I used an aftermarket unit.
No SeS light went on this time. I have a buddy with a real OBD1 scanner... I went old school and used a paper clip. Maybe the scanner will tell me something that the paper clip couldn't. I wonder if there's a big difference between an aftermarket knock sensor and a GM one? I used an aftermarket unit.
Thread Starter
Burning Brakes
Joined: Aug 2006
Posts: 1,123
Likes: 1
From: Rockland County NY
Won't the chip tune override what i would set the timing at? Also, it only does it once in a while...not all the time. 30 miles of stop and go the other day it only did it twice and only for a second or two at mild acceleration from a dead stop. If it was a timing problem, wouldn't it do it all the time?
Racer
Joined: Apr 2011
Posts: 296
Likes: 1
From: Tipp City Ohio
Won't the chip tune override what i would set the timing at? Also, it only does it once in a while...not all the time. 30 miles of stop and go the other day it only did it twice and only for a second or two at mild acceleration from a dead stop. If it was a timing problem, wouldn't it do it all the time?
