GaryDoug

Does the code pop back up if you leave the meter connected? What model multimeter are you using?

Try this test: Disconnect the battery. Measure the voltage at the KS end of the wire with the KS disconnected. Wait until the voltage measures zero volts. Then measure the resistance of the wire to ground. Mine measures 4.15 K Ohms.

Jank315

Yes the code pops up no matter what after about 5 seconds after starting. I'm using a fluke meter I will test the wire like you mentioned above and report back. What are your thoughts on if I fried the new knock module? I just cant see there being another problem if the circuit is in shape and I am getting the correct voltage going into the PCM. I have also checked right at the back of the D22 with it unplugged to make sure that pin connection is sound. I really appreciate all the help and suggestions.

Jank315

Did the test above. After no voltage was present the wire had 4.17K ohms.

GaryDoug

Well that confirms that the wire is ok to the pcm and the pcm input has the right resistance.
Now I am stumped unless the new module is bad also. Or maybe there is another failure mode of which I am not aware.

Did the code come back after making that measurement?

GaryDoug

I know what I would do next, but it may not be an option for you. I would connect an o-scope probe to the sensor and watch the voltage while the engine is started until the code sets. Perhaps there is some kind of intermittent connection somewhere. The 5v reference that supplies the sensor module also goes to several other places.

Jank315

Yes the code came right back on about 3-5 seconds after startup. I don’t have a o-scope. I did measure voltage on the sensor wire with it hooked up as I started the car and it stayed rocked steady at 2.41v even when it set the code.

Jank315

I’m going to try one more KM. I don’t really know what else it could be. It just doesn’t make sense. Everything I test is coming back normal.

Jank315

Tried another KM In the new PCM. Same exact results. I now have the sensor lead D22 coming right out of the back of the PCM straight into a 3.9k resistor to the chassis ground. There is no way the lead is bad or open yet I still get the code. It has to be associated with something else. Very frustrating to say the least. As soon as I clear the DTC’s the malf43c pops back up in a matter of seconds then when I start the car the DTC comes right back. Is it possible maybe the 94/95 scan is picking up the incorrect code? I’m just trying to think of where to look next. It’s getting ridiculous.

Injuneer

Damaged or corroded pin(s) in the knock module socket ????

Jank315

I’ve checked the socket very closely. 2 pcms doing the same thing. 3 different knock modules.

Jank315

Circuit is completely isolated so I know it’s not the lead. I wish I could scan with something else just to see if I’m getting the same code.

Jank315

Scanned with FreeScan says same thing dtc43 except it says esc failure.

Injuneer

That's because FreeScan is using old, generic terminology (electronic spark control - 3rd Gen term). Use Shoebox's code list, specifically for 93-95 LT1’s.

https://www.camaroz28.com/forums/com...95-lt1-874306/

Or download the 95 factory service manual:

https://www.mediafire.com/?40mfgeoe4ctti

Jank315

That’s what I figured. Does anybody know where the PCM sends the signal from the knock module to or what component retards the timing?

Jank315

I went over the whole harness and have found some pretty bad connections. The KS wire was cut along with the sensor ground and just wrapped up in the harness. Also the grounds on the coil were in bad shape The only one connected were the tans the other ground and chassis ground were both disconnected. After fixing all of that still exact same code. Figured all the disconnected grounds would have been causing problems but it must have just been grounding everything through the 2 tan wires.