Electronic Spark Control/knock Sensor

[martens]

I picked up a 95 GMC Sierra with the 5.0 L. It was showing 6 trouble codes when I got it and I got them all fixed except for trouble code 43. I replaced the knock sensor and no change. I replaced the ESC module and while it runs better, I am still getting trouble code 43. The wiring all looks good although I haven't checked with a continuity tester.

 

Any thoughts? I thought un hooking the negative battery cable should have cleared the code assuming that the knock sensor and module fixed the problem.