Diagnostic Aids

Check knock sensor signal circuit for a potential open or short to ground. An open knock signal circuit would cause the 5-volt reference to remain high at ECM knock signal terminal. A short to ground in the knock signal circuit would cause the 5-volt reference signal to pull low to near zero volts. Resistance to ground through the knock sensor should be 3300-4500 ohms. Also check for proper installation of MEM-CAL.

Fig 1: Code 43, Schematic, ESC Error Without ESC Module

Fig 2: Code 43, Flow Chart, ESC Error Without ESC Module