I have a '92, LT1 automatic. My SES light came on, and noticed a slightly rough idle. I scanned, and found code 43, "Electronic Spark Control (ESC) Failure". Ok, now what to do?? What to check, etc. Thanks!

 

Start with the knock sensors. How many miles?

 

104,000!!! Maybe replace the sensors, then maybe the knock module?? (BTW,I do use Sunoco Ultra gas , 94 octane?

 

great gas! Love that stuff... however, at 104k, replace the sensors.

There is no module... it's integrated into the ECM.

You will have to drain coolant! The knock sensors are the engine's block drains... and there are 2 of them. One on each side. To remove, you first have to remove their shields. Sadly, the only way is to jack up the car and get under... icky.

 

Thanks! Yeah that gas is good stuff, worth the $$! Thats perfect about replacing the knock sensors, and having to drain coolant , because I'm planning to replace the coolant hoses and a flush/refill, so perfect! Thanks , Bogus! ( Thanks for the info on the "knock module", I'm still learning about 'Vettes here, see that, I learned something today! ) Ok, thanks again

 

Be sure and torque those sensors back in at 15 lbs., too. Do not use any tape or thread compound. The orange tape that comes on the new sensors is all you need.

 

Ok, yhanks for the tip!

 

Ok,

 

Ok, thanks

 

Ok, thanks for

 

Ok, thanks for the

 

OK, thanks for the tip!

 

What the HELL is wrong with this site anymore???? And slowwwwwww too......

 

I hope this will give you some insight into the code 43. With the milage you have on the car I would certainly try cleaning the wire connectors.

As information this article was written for me by my cousin who has had articles published on designing engines.

Good luck with resolving this problem.

Knock Sensor

A quick look at “spark-knock” fundamentals.

For the record we will say that the knock is a non-regulated quick rise in pressure generally confined to a pocket in the combustion chamber.

Now let us see if we can find out how this “quick rise in pressure” occurs. There are a number of ways but we will only mention two. One is a hot carbon spark setting off the mixture generally in the squish area of the head before the piston reaches top dead center of compression. That is rare these days.

The second would be low octane gas that ignites spontaneously at a low compression pressure. Even in today’s world of good grades of gas there are some combustion cavity shapes that are better than others so if one got a poor tank of gas knocking could come into play.

This quick rise in pressure from a sensor standpoint produces in the sensor a quick rise in both resistance and voltage. But the voltage can’t rise beyond the fixed ratio of the number of turns in the coil between the low voltage side and the high voltage side therefore the sensor can only sense a rise in resistance.

The ECU has a program to sense the rise in resistance from normal piston motion compressing the mixture. Anything below max RPM piston velocity will not trigger the knock sensor. But if a very quick rise in pressure from a knock occurs the sensor will sense both the rise in pressure and the resistance to the spark across the spark plug gap.

Even if the knock is not audible the sensor will indicate knock has occurred.

Now a loose wire will also be sensed as higher resistance to the battery voltage to the sensor. Its only way of telling you that something is wrong is to tell you knock has occurred. If there was a loose wire program it would indicate “loose wire” but since there is no such program it can’t tell you exactly what is wrong.

With this in mind a code H43 which is a knock sensor code may not necessarily mean the sensor is bad but rather a wire is loose or broken.

Author:
Leonard A. Karber

By the way my helms manual mentions checking for dirty contacts also.

 

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Yep, got nothing else to do, and its especially fun when it takes 5 mins in between to post each one! Yay!!!