Is code 43 electronic spark control failure the ESC or knock sensor?
Thread Starter
Race Director
Joined: Sep 2001
Posts: 14,682
Likes: 753
From: NEwhere Ohio
Is code 43 electronic spark control failure the ESC or knock sensor?
My service engine light comes on a few seconds and then goes out. Does this even after disconnecting the battery for a while.
A quick scan on my scan tool shows 'Code 43 Electronic Spark Control Failure'.
I have heard people say that a Code 43 is knock sensors, or electronic spark control (the thing behind the ignition coil).
How do I know for sure which one it is (Whether its knock sensors, or ESC)?
I should mention the car still drives normally, and the light goes out after a few seconds, but it does come on to remind me....will my car breakdown on the road?
A quick scan on my scan tool shows 'Code 43 Electronic Spark Control Failure'.
I have heard people say that a Code 43 is knock sensors, or electronic spark control (the thing behind the ignition coil).
How do I know for sure which one it is (Whether its knock sensors, or ESC)?
I should mention the car still drives normally, and the light goes out after a few seconds, but it does come on to remind me....will my car breakdown on the road?
Le Mans Master
Joined: Jul 2002
Posts: 5,818
Likes: 2
From: Alive and well in Burlington NC
Re: Is code 43 electronic spark control failure the ESC or knock sensor? (dizwiz24)
My 91 did the same thing. Code 43. Turned out to be a failed knock sensor. Had voltage going onto it, but none coming out. Replaced it and all is well (well, at least I don't get the code 43 any more!).
Pro
Joined: Jan 2001
Posts: 681
Likes: 2
From: Newton (Wichita Area) Kansas
Re: Is code 43 electronic spark control failure the ESC or knock sensor? (dizwiz24)
This is what I've learned lately about knock sensors:
The knock sensor is part of the ESC system in GM OBD I vehicles. Knock sensors are like oxygen sensors. There is no oxygen or knock sensor power supply. That single wire carries a millivoltage signal generated by the sensor itself. This signal is referenced (grounded) by the engine block. Knock sensors produce an AC millivolt signal when the engine is running, even at idle, whereas an oxygen sensor signal is more DC like.
So it kind of sounds like your knock sensor is failing or worn out. There are no specs for the signal output but you might try to verify that there is an AC signal there. Otherwise replace it and see what happens.
The knock sensor is part of the ESC system in GM OBD I vehicles. Knock sensors are like oxygen sensors. There is no oxygen or knock sensor power supply. That single wire carries a millivoltage signal generated by the sensor itself. This signal is referenced (grounded) by the engine block. Knock sensors produce an AC millivolt signal when the engine is running, even at idle, whereas an oxygen sensor signal is more DC like.
So it kind of sounds like your knock sensor is failing or worn out. There are no specs for the signal output but you might try to verify that there is an AC signal there. Otherwise replace it and see what happens.
Safety Car
Joined: Feb 2001
Posts: 4,397
Likes: 0
From: Looks like I picked the wrong week to stop sniffin glue Orlando
Re: Is code 43 electronic spark control failure the ESC or knock sensor? (dizwiz24)
Just had the same problem on my 1990. Knock sensor was fine.
ECM was bad.
ECM was bad.
Le Mans Master
Joined: Oct 1999
Posts: 9,713
Likes: 3
From: Sachse Texas
Cruise-In I Veteran
Cruise-In II Veteran
Re: Is code 43 electronic spark control failure the ESC or knock sensor? (dizwiz24)
Every time I get a 43 I put a new knock sensor in and it solves the error code. You have to install them to no more than 10-14 ft lbs of torque or they will not last you very long either.
Race Director
Joined: Jun 2001
Posts: 10,956
Likes: 681
From: Marlboro country MA
Re: Is code 43 electronic spark control failure the ESC or knock sensor? (Vette92)
I had a code 43 last year. Jumped through lots of hoops, looking for the cause. Turned out I had a bad ECM. Replaced the ECM and no problems since.
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