Code 43 Questions
06-16-2008 | 04:58 PM
#1
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Joined: Jul 2007
Posts: 777
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From: Tampa/New Hampshire
Car: 91 camaro RS, 87 T/A
Engine: 350 TBI, 305 TPI
Transmission: 700r4
Axle/Gears: 4th Gen 3.42/BW 3.45
Code 43 Questions
So while i was driving today, under hard acceleration while merging my car threw an SES. Came home, read the code, turned out to be a code 43. Restarted the car, it idled fine, drove it around and still no code. Did some research and found out a code 43 is low voltage in the knock system or something along those lines. Drove the car again under hard acceleration, 4 times from a stop all the way to about 60 and no code. Now i just replaced my Knock sensor and ESC to 350 ones because of my swap, im still running the stock 305 chip in my 350TBI but everything else is for a 350. Is there any checks that i can do to verify that my new Knock sensor and ESC is working properly without waiting for another light to come on?
06-16-2008 | 05:33 PM
#2
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Joined: Jun 2008
Posts: 62
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Car: '91 RS
Engine: 355 on a stand
Transmission: 700R4
Axle/Gears: 3:42
Re: Code 43 Questions
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 at the rear of the engine 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
ESC is used to sense spark knock (pinging) and retard the timing to eliminate it. A knock sensor (located at the rear of the engine 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
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