CODE 43 - ESC ERROR (WITHOUT ESC MODULE) Buick Park Avenue I

CODE 43 - ESC ERROR (WITHOUT ESC MODULE)

Note. Test numbers refer to numbers on diagnostic chart. If an audible knock is heard from engine at idle, repair internal engine problems before proceeding.

1. If tapping on engine does not produce a knock signal on scan tester, try tapping engine closer to sensor before proceeding.
2. ECM supplies a 5-volt reference signal on knock sensor line. With knock sensor connected, this signal is pulled low to about 2.5 volts. Knock signal, which is an AC signal, rides on this 2.5-volt DC signal.
3. This test determines if knock sensor is faulty or if ESC portion of MEM-CAL is faulty.

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

Code 43 Schematic W/O ESC Module (All Models) ESC Error. Scheme 217

Code 43 Flow Chart W/O ESC Module (All Models) ESC Error. Scheme 218