Getting Code 43 - Knock Sensor
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Racer
Joined: Jul 2001
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Getting Code 43 - Knock Sensor
What the heck is this thing really doing? Sensing for "knocking" and sending a signal to the ECM to retard the timing, right? There's a procedure in the ECM to test the knock sensor at "strt-up" and I have no problems there, but then why is this an issue when I give it a little too much gas in too low of a gear?
I know I needed to downshift or give it enough gas to allow the 4+3 to come out of OD, but if I don't.... what's going on here to set the code?
If I'm to replace the sensor, how much for the part?
I know I needed to downshift or give it enough gas to allow the 4+3 to come out of OD, but if I don't.... what's going on here to set the code?
If I'm to replace the sensor, how much for the part?
Le Mans Master
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I've got the automatic version of this going on at:
http://forums.corvetteforum.com/showthread.php?t=874729
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Originally Posted by 86VetteBill
What the heck is this thing really doing? Sensing for "knocking" and sending a signal to the ECM to retard the timing, right? There's a procedure in the ECM to test the knock sensor at "strt-up" and I have no problems there, but then why is this an issue when I give it a little too much gas in too low of a gear?
I know I needed to downshift or give it enough gas to allow the 4+3 to come out of OD, but if I don't.... what's going on here to set the code?
If I'm to replace the sensor, how much for the part?
I know I needed to downshift or give it enough gas to allow the 4+3 to come out of OD, but if I don't.... what's going on here to set the code?
If I'm to replace the sensor, how much for the part?
Sometimes these things are "model year specific"!I can tell you this, 88 and maybe other years sufferred from an Electronic spark control module that was/is overly sensitive to any noise such as headers for example.
Solution! Switch the module to NAPA ESC 312. I believe the module is on the passenger side (it is on 88's) up near the hood strut.
I got this code when the wire from the knock sensor got disconnected at the sensor itself. This could also occur if the terminal on the knock sensor or the wire was dirty or if the knock sensor itself is bad.
This sensor is looking for noise, not necessarily spark knock. Keep that in mind. Like I said, headers will set it off and so will other "noises" in the area
Just MHO
Le Mans Master
Joined: Jul 2002
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From: Alive and well in Burlington NC
If you're setting a code 43, it means that the ECM has detected a problem in the knock sensor circuit not necessarily that you are getting retard. Could be the sensor itself or the wiring harness.
Drifting
Joined: Sep 2003
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From: 1990 383 Stroker Baltimore Maryland
The sensor runs about $40 dollars and simply screws into your engine. When I first got my car all my sensors were going up from overheating and this was one of the codes I received. I would hit the gas and then all of a sudden the engine would bog down like I lost 75% of my power. What happened was the sensor was defective/worn out and it was sending a false code to the ECM and the timing would lower causing the lose of power.
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From: Soddy Daisy TN
Originally Posted by SupaVette
Sounds like you're getting detonation at low rpm under load, and it can't retard enough :?
Mine was doing the same thing a few days ago. Under heavy accel it would ping no matter where my timing was. I had just got this engine back together and overlooked the throttle position sensor. I had taken it off the TB to clean it and forgot to reset the voltage on it prior to running the motor. It diddn't matter how much retard...still pingged. Finally I checked the tps voltage and it was way too low. I adjusted my voltage back up, reset base timing and she hasn't pingged since. She runs alot better too. Just something to consider.
By the way, an easy way to check your TPS voltage without buying or making a test plug is to insert 2 safety pins into the plug, (just lay it flat against the wire pointing toward the plug and it will slide right into the plug), so they make contact with the top and middle wires. Now you have easy access with a volt meter.
Le Mans Master
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From: Philadelphia Burbs
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Re: Getting Code 43 - Knock Sensor
Originally Posted by drumboytroy
Mine was doing the same thing a few days ago. Under heavy accel it would ping no matter where my timing was. I had just got this engine back together and overlooked the throttle position sensor. I had taken it off the TB to clean it and forgot to reset the voltage on it prior to running the motor. It diddn't matter how much retard...still pingged. Finally I checked the tps voltage and it was way too low. I adjusted my voltage back up, reset base timing and she hasn't pingged since. She runs alot better too. Just something to consider.
By the way, an easy way to check your TPS voltage without buying or making a test plug is to insert 2 safety pins into the plug, (just lay it flat against the wire pointing toward the plug and it will slide right into the plug), so they make contact with the top and middle wires. Now you have easy access with a volt meter.
By the way, an easy way to check your TPS voltage without buying or making a test plug is to insert 2 safety pins into the plug, (just lay it flat against the wire pointing toward the plug and it will slide right into the plug), so they make contact with the top and middle wires. Now you have easy access with a volt meter.
Thread Starter
Racer
Joined: Jul 2001
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Great - I'll check the TPS. I had that set prior to going into Chevy to get some things looked at and they replaced the ECM for me. They also cleaned the TB, so maybe they didn't check the TPS afterwards? I'll check (too late for the pins - I already cut away a little of the insulation on the wires! 
)
The sensor would set a 43 once in awhile before taking it into Chevy, but now it's too often - not every day, but more than I'd like to see it. I'll also check into pricing that knock sensor since I want to flush and replace the coolant anyway and I know I'll get a bath when I pull out that sensor from the block!
)The sensor would set a 43 once in awhile before taking it into Chevy, but now it's too often - not every day, but more than I'd like to see it. I'll also check into pricing that knock sensor since I want to flush and replace the coolant anyway and I know I'll get a bath when I pull out that sensor from the block!
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Inspect the sensor for dirt, oil and other contaminants. If its dirty, that can cause Code 43 at start-up like you're describing.
Drifting
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From: Charlestown IN
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Allright, here's the answer, believe it or not. There is an ESC (electronic spark control) module on the passengerside, facing out, next to the heater motor. Find out which wire, I think it's the black one, is for ground and run another wire from the module to a good ground. This'll fix it.
Le Mans Master
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From: Philadelphia Burbs
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