code 43, ESC/ knock and jumping spark?
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code 43, ESC/ knock and jumping spark?
so i'm posting this for my buddys 1990 GMC 1500 4x4 5.7 tbi. i've been trying get the darn thing to stop throwing codes..... code 43, ESC. things that have been replaced spark plug wires, spark plugs, injectors, EGR valve and solenoid and the ESC module. timing set at 2 degrees advanced have tried 87/89/91 octane with no help
on the highway after a bit of driving and then going WOT for a while it throws code 43 and starts to stumble and run like crap, were trying to get it smogged but the unburned fuel readings bounce up and down from good to very very bad, while the timming gun is connected I will notice 2 or 3 real fast strobes as if the gun was pickimg up 2 or 3 different sparks at the same time then it goes back to a normal firing order. and repeats every 5-10 seconds
after the light comes on and it starts to bog down and miss, if you turn it off and start it right back up it goes to normal and runs great untill the SES light returns
the motor was rebuilt about 10,000 miles agovwith about 230,000 total on the clock. any ideas would be great
one last thing when i first looked at it after my friend purchased it, it idled very high, i had to turn the idle adjustment screw back a bit to get it below 1,200 also all vacumn lines look good and hooked up properly.
anyone have any ideas
on the highway after a bit of driving and then going WOT for a while it throws code 43 and starts to stumble and run like crap, were trying to get it smogged but the unburned fuel readings bounce up and down from good to very very bad, while the timming gun is connected I will notice 2 or 3 real fast strobes as if the gun was pickimg up 2 or 3 different sparks at the same time then it goes back to a normal firing order. and repeats every 5-10 seconds
after the light comes on and it starts to bog down and miss, if you turn it off and start it right back up it goes to normal and runs great untill the SES light returns
the motor was rebuilt about 10,000 miles agovwith about 230,000 total on the clock. any ideas would be great
one last thing when i first looked at it after my friend purchased it, it idled very high, i had to turn the idle adjustment screw back a bit to get it below 1,200 also all vacumn lines look good and hooked up properly.
anyone have any ideas
Last edited by 1988-305-tbi; Mar 27, 2010 at 05:57 AM.
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Re: code 43, ESC/ knock and jumping spark?
You may have couple of problems, but let see about CODE 43
Trouble Code 43 indicates that there may be a malfunction in the Electronic Spark Control (ESC) circuit.
ESC is used to sense spark knock (pinging) and retard the timing to eliminate it. A knock sensor (located on passenger side above oil pan rail, in the block) sends signals to an ESC module which then signals the ECM that knocking is being detected. The ECM will retard the timing by as much as 20 degrees in 1 degree increments. A loss of knock sensor signal or loss of ground at the ESC module will cause the signal at the ECM to remain high. The ECM will act as if no knock is present, and may possibly result in engine damage, if there is detonation.
Loss of the ESC signal to the ECM will cause the ECM to constantly retard the timing to its maximum. This results in sluggish performance and a Code 43.
The conditions for setting this code are:
Typical causes for this code include:
1) Open or shorted knock sensor
2) Loose knock sensor
3) Excessive mechanical noise within engine
4) Improper or incorrectly installed PROM or CALPACK in the ECM or defective ECM
5) Intermittent open in the EST line to the ignition module
In EFI system ECM swings fuel mixture from rich to lean and back - this is normal and you would see using gas analyzer. However, if you have old or 'lazy' O2 sensor ECM might be forcing fuel mixture too rich (higher voltage) or too lean (low O2 voltage). Common fix is to replace O2 with a new one - use Delco unit as other MFG O2 sensors have a different response characteristics.
If you see occasional double strobing with your timing light check for distributor cross arching - due to carbon build up, worn terminals or center button. Take a close look at ignition wires for bad insulation or damage and the rest of ignition system for loose grounds, or bad components.
//RF
Trouble Code 43 indicates that there may be a malfunction in the Electronic Spark Control (ESC) circuit.
ESC is used to sense spark knock (pinging) and retard the timing to eliminate it. A knock sensor (located on passenger side above oil pan rail, in the block) sends signals to an ESC module which then signals the ECM that knocking is being detected. The ECM will retard the timing by as much as 20 degrees in 1 degree increments. A loss of knock sensor signal or loss of ground at the ESC module will cause the signal at the ECM to remain high. The ECM will act as if no knock is present, and may possibly result in engine damage, if there is detonation.
Loss of the ESC signal to the ECM will cause the ECM to constantly retard the timing to its maximum. This results in sluggish performance and a Code 43.
The conditions for setting this code are:
- Engine is running
- ESC input signal has been low more than 2.23 seconds
Typical causes for this code include:
1) Open or shorted knock sensor
2) Loose knock sensor
3) Excessive mechanical noise within engine
4) Improper or incorrectly installed PROM or CALPACK in the ECM or defective ECM
5) Intermittent open in the EST line to the ignition module
In EFI system ECM swings fuel mixture from rich to lean and back - this is normal and you would see using gas analyzer. However, if you have old or 'lazy' O2 sensor ECM might be forcing fuel mixture too rich (higher voltage) or too lean (low O2 voltage). Common fix is to replace O2 with a new one - use Delco unit as other MFG O2 sensors have a different response characteristics.
If you see occasional double strobing with your timing light check for distributor cross arching - due to carbon build up, worn terminals or center button. Take a close look at ignition wires for bad insulation or damage and the rest of ignition system for loose grounds, or bad components.
//RF
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Re: code 43, ESC/ knock and jumping spark?
Great info RF, ESC modules are sorta pricey, $75-$100 new. If you can find one on a car or truck thats running....(5.7)...do a swap... see if it works right. There used to be a lot of them in the salvage yards, but they are getting harder to find.
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From: San Diego, California
Car: Trailblazer EXT 4.2 (Firebird Form)
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Re: code 43, ESC/ knock and jumping spark?
in total darkness fire up the car and look for arcing ... make sure that the spark plug wires aren't touching each other... if you have an EGR, make sure it's operational...
Thread Starter
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Joined: Mar 2004
Posts: 550
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From: SoCal "Riverside"
Re: code 43, ESC/ knock and jumping spark?
yeah i have tried 3-4 ESC's out of junkyard cars, the EGR is 2 weeks old, i sprayed/misted the sparkplug wires while the engine was running but couldn't see any arcing.
i'm thinking it maybe the knock sensor/ bad distributor, thanks again for the replys
i'm thinking it maybe the knock sensor/ bad distributor, thanks again for the replys
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Re: code 43, ESC/ knock and jumping spark?
You may have couple of problems, but let see about CODE 43
Trouble Code 43 indicates that there may be a malfunction in the Electronic Spark Control (ESC) circuit.
ESC is used to sense spark knock (pinging) and retard the timing to eliminate it. A knock sensor (located on passenger side above oil pan rail, in the block) sends signals to an ESC module which then signals the ECM that knocking is being detected. The ECM will retard the timing by as much as 20 degrees in 1 degree increments. A loss of knock sensor signal or loss of ground at the ESC module will cause the signal at the ECM to remain high. The ECM will act as if no knock is present, and may possibly result in engine damage, if there is detonation.
Loss of the ESC signal to the ECM will cause the ECM to constantly retard the timing to its maximum. This results in sluggish performance and a Code 43.
The conditions for setting this code are:
Typical causes for this code include:
1) Open or shorted knock sensor
2) Loose knock sensor
3) Excessive mechanical noise within engine
4) Improper or incorrectly installed PROM or CALPACK in the ECM or defective ECM
5) Intermittent open in the EST line to the ignition module
In EFI system ECM swings fuel mixture from rich to lean and back - this is normal and you would see using gas analyzer. However, if you have old or 'lazy' O2 sensor ECM might be forcing fuel mixture too rich (higher voltage) or too lean (low O2 voltage). Common fix is to replace O2 with a new one - use Delco unit as other MFG O2 sensors have a different response characteristics.
If you see occasional double strobing with your timing light check for distributor cross arching - due to carbon build up, worn terminals or center button. Take a close look at ignition wires for bad insulation or damage and the rest of ignition system for loose grounds, or bad components.
//RF
Trouble Code 43 indicates that there may be a malfunction in the Electronic Spark Control (ESC) circuit.
ESC is used to sense spark knock (pinging) and retard the timing to eliminate it. A knock sensor (located on passenger side above oil pan rail, in the block) sends signals to an ESC module which then signals the ECM that knocking is being detected. The ECM will retard the timing by as much as 20 degrees in 1 degree increments. A loss of knock sensor signal or loss of ground at the ESC module will cause the signal at the ECM to remain high. The ECM will act as if no knock is present, and may possibly result in engine damage, if there is detonation.
Loss of the ESC signal to the ECM will cause the ECM to constantly retard the timing to its maximum. This results in sluggish performance and a Code 43.
The conditions for setting this code are:
- Engine is running
- ESC input signal has been low more than 2.23 seconds
Typical causes for this code include:
1) Open or shorted knock sensor
2) Loose knock sensor
3) Excessive mechanical noise within engine
4) Improper or incorrectly installed PROM or CALPACK in the ECM or defective ECM
5) Intermittent open in the EST line to the ignition module
In EFI system ECM swings fuel mixture from rich to lean and back - this is normal and you would see using gas analyzer. However, if you have old or 'lazy' O2 sensor ECM might be forcing fuel mixture too rich (higher voltage) or too lean (low O2 voltage). Common fix is to replace O2 with a new one - use Delco unit as other MFG O2 sensors have a different response characteristics.
If you see occasional double strobing with your timing light check for distributor cross arching - due to carbon build up, worn terminals or center button. Take a close look at ignition wires for bad insulation or damage and the rest of ignition system for loose grounds, or bad components.
//RF
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