I just scanned my Camaro and this is the only trouble code I got. It says in the manual that code 43 is the ESC (electronic spark control) or EST (electronic spark timing). I looked in the glossary, and it said ESC is basically the knock sensor. I don't know what EST is. Is that the opti? Anyways, the symptoms are that it runs a little rough, and the fans won't kick on, so it overheats (don't know why, the fan relay is good). Any ideas what my problem is here??? What's the solution? If it's the knock sensor, should I just disconnect it? Do I need to replace the opti?

 

43 Knock Sensor (KS) circuit. Info.

 

I've got a 93, so that can only mean the KS is bad, the wiring is bad, or the ECM is bad, right??

 

First reset the code and see if it returns. If it does, do the following.

Pull the connector off the KS and with the key on confirm you have 5volts from there to ground at the connector. If not, go back to the PCM connector and measure at the PCM for 5volts to ground. If it's there and not at the KS connector, you obviously have a wire problem. On a 94 the KS signal is on the dark blue wire that goes to the blue PCM connector but I don't know if it's the same for a 93. Rob may know what connector it's on in a 93. If the voltage you read is higher than 5 volts,(more likely 12V) when you measured at the KS connector, there is a short to battery voltage along the wire somewhere.

If that's ok, measure the resistance of the KS to ground with the connector off. Should read 3.3K to 4.5K ohms. If it is higher, either the KS is not grounded properly where it screws in, or the KS is bad. If it is a lower resistance, the KS is bad.

If all that check's out and the connections are good, the PCM is bad. Try first having it reflashed before you go buying a new one. Any Auto-Value store will do it for $69.00 but I doubt the PCM is bad. Very rarely do the PCM's go bad so if you get to that conclusion, go back and check again.