Code 43 ESC/Knock on an 85
Thread Starter
Race Director
Joined: Aug 2000
Posts: 10,712
Likes: 0
From: Manitoba
Code 43 ESC/Knock on an 85
Hey guys, I finally got the rest of my ECM errors cleared up and have one left. When I am driving the car and stab the gas I get a code 43. If I drive normally it doesn't bother. I can rev the car up to 4000 RPM when it is standing still and I don't hear any knocking, but they will generally only do that when they are under load right?
Right now I have regular gas in the car (88 octane), I have 3 bars left on the fuel indicator, and I dumped in a can of Penzoil Octane booster and ran it for quite a while, doesn't seem to have made a difference. I also dumped in a can of STP fuel injector cleaner. There is no way to get Premium fuel out here so that is out of the question right now.
I have the upgraded PROM for my car from GM.
Do I have to lift the car to get at the knock sensor? It looks to be pretty difficult to get at it from up top.
Anything specific I should check?
Right now I have regular gas in the car (88 octane), I have 3 bars left on the fuel indicator, and I dumped in a can of Penzoil Octane booster and ran it for quite a while, doesn't seem to have made a difference. I also dumped in a can of STP fuel injector cleaner. There is no way to get Premium fuel out here so that is out of the question right now.
I have the upgraded PROM for my car from GM.
Do I have to lift the car to get at the knock sensor? It looks to be pretty difficult to get at it from up top.
Anything specific I should check?
Racer
Joined: Nov 2002
Posts: 471
Likes: 0
From: Queens NY
Re: Code 43 ESC/Knock on an 85 (DF)
I have to do mine as well. You can jack the car up, and it should be near the starter towards the bottom of the block. Be careful when you take it out because coolant will go everywhere. Be ready to plug it real quick!
Also while we're on the topic.. my knock sensor won't budge.. anyone know how to get that sucker out?? :banghead:
Also while we're on the topic.. my knock sensor won't budge.. anyone know how to get that sucker out?? :banghead:
Instructor
Joined: Sep 2002
Posts: 136
Likes: 0
From: Port Moody BC
Re: Code 43 ESC/Knock on an 85 (65Z01)
Seems to be a lot of Knock problems with earlier model C4's.
Here is my story. I get engine detonation during heavy load which trips the engine check light and records a code 43. Timing is correct.
Coolant needed replacement so I replaced the Knock Sensor. No change.
Replaced ESC. No change.
My Mechanic tried a brand new computer. No change.
With a scanner hooked up and the engine running ... if you tap on the side of the block ... should it not register knocks??? Mine does not.
I am getting a little frustrated. Any other suggestions???
Not sure if ESC I replaced is the new upgraded one mentioned on your site.
I am lost and so is my mechanic. I understand that there is a whole list of things that can probably cause detonation but is there something I am forgetting to check???
And one more thing ... there is no carbon buildup and I use 94 octane Chevron Gas.
HELP!!!!!
Gary
:seeya
[Modified by drvette85, 2:22 AM 6/1/2003]
Here is my story. I get engine detonation during heavy load which trips the engine check light and records a code 43. Timing is correct.
Coolant needed replacement so I replaced the Knock Sensor. No change.
Replaced ESC. No change.
My Mechanic tried a brand new computer. No change.
With a scanner hooked up and the engine running ... if you tap on the side of the block ... should it not register knocks??? Mine does not.
I am getting a little frustrated. Any other suggestions???
Not sure if ESC I replaced is the new upgraded one mentioned on your site.
I am lost and so is my mechanic. I understand that there is a whole list of things that can probably cause detonation but is there something I am forgetting to check???
And one more thing ... there is no carbon buildup and I use 94 octane Chevron Gas.
HELP!!!!!
Gary
:seeya
[Modified by drvette85, 2:22 AM 6/1/2003]
Pro
Joined: Jul 1999
Posts: 741
Likes: 0
From: Eagle IDAHO
Cruise-In I Veteran
Cruise-In II Veteran
Re: Code 43 ESC/Knock on an 85 (drvette85)
I had that same problem on my 85. Turned out that when I reassembled the engine after the rebuild I put too much torque on the knock sensor and it made it too sensitive. It is a piezioelectric crystal that generates a voltage when stressed. I removed it retorqued it to specs and the problem ceased. Sorry, but I don't remember what the torque spec is.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Code 43 ESC/Knock on an 85 (drvette85)
The ECM checks the knock sensor once per startup after coolant is above 195 deg F; so a 180 deg stat should eliminate the code 43 though it realy doesn't resolve the cause.
For the ping issue, if you tap the block near the knock sensor idle RPM should drop; if not replace the knock sensor.
To test the ESC module let the engine idle for 1 minute or till the SES comes on. If no code 43, the ESC is OK; if code 43 probe the Blk wire near pin C with a DMM probe. If over 6Vdc there is a faulty connection at the ESC. If ok, stop the engine with ignition on. If voltage is over 6Vdc replace the ESC.
If still a problem it could be in the ECM or it's connector.
I suggest a copy of "Chevy TPI Fuel Injection Swapper's Guide" by John Baechtel for thorough diagnostics for each trouble code and much more.
For the ping issue, if you tap the block near the knock sensor idle RPM should drop; if not replace the knock sensor.
To test the ESC module let the engine idle for 1 minute or till the SES comes on. If no code 43, the ESC is OK; if code 43 probe the Blk wire near pin C with a DMM probe. If over 6Vdc there is a faulty connection at the ESC. If ok, stop the engine with ignition on. If voltage is over 6Vdc replace the ESC.
If still a problem it could be in the ECM or it's connector.
I suggest a copy of "Chevy TPI Fuel Injection Swapper's Guide" by John Baechtel for thorough diagnostics for each trouble code and much more.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
2027 Corvette vs The World: Every C8 vs Its Closest Competitor
Joe Kucinski
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
Team Owner
Joined: Oct 2000
Posts: 96,443
Likes: 9
From: Fort Knox, KY
Cruise-In IV Veteran
Cruise-In VI Veteran
Cruise-In VII Veteran
Cruise-In VIII Veteran
Re: Code 43 ESC/Knock on an 85 (CarAteMyMoney)
I have to do mine as well. You can jack the car up, and it should be near the starter towards the bottom of the block. Be careful when you take it out because coolant will go everywhere. Be ready to plug it real quick!
Also while we're on the topic.. my knock sensor won't budge.. anyone know how to get that sucker out?? :banghead:
Also while we're on the topic.. my knock sensor won't budge.. anyone know how to get that sucker out?? :banghead:
When you put it back in, tighten to SPEC. using a torque wrench or you could get CODE 43 again. Also, the orange coating on the threads is all you need. DO NOT add plumbing tape or thread compound or you could blunt your sensor's ability to listen for pre-detonation (spark knock) in those cylinders. :thumbs:
Melting Slicks
Joined: May 2001
Posts: 3,270
Likes: 26
From: Winchester VA
Cruise-In V Veteran
Re: Code 43 ESC/Knock on an 85 (DF)
"I have the upgraded PROM for my car from GM"
I'm not sure what exactly that is, however, most performance oriented PROMS have a more aggressive spark curve which requires the use of premium fuel. Since that is not available, try switching back to your stock prom and see what happens.
I'm not sure what exactly that is, however, most performance oriented PROMS have a more aggressive spark curve which requires the use of premium fuel. Since that is not available, try switching back to your stock prom and see what happens.
1st Gear
Joined: Jul 2011
Posts: 1
Likes: 0
okay i have the same issue and this thread is going all over the place...
torque for the knock sensor is _______ ?
timing is suppose to be _______ ?
and how do you check if it is registering a knock signal, do you need to have an aldl cable and a program to c it or can you do it by back-probing the sensor? and if you need a program (i am using winaldl) what is the abbreviation for the knock sensor? for example IAC is idle air control valve and TPS is throttle position sensor. so what is it for knock sensor? and there is no esc or knk so preferably someone who is using winaldl would know.
torque for the knock sensor is _______ ?
timing is suppose to be _______ ?
and how do you check if it is registering a knock signal, do you need to have an aldl cable and a program to c it or can you do it by back-probing the sensor? and if you need a program (i am using winaldl) what is the abbreviation for the knock sensor? for example IAC is idle air control valve and TPS is throttle position sensor. so what is it for knock sensor? and there is no esc or knk so preferably someone who is using winaldl would know.
You should start a new one.
