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Home >> Buick >> 1991 >> Reatta 2D Convertible >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - Pcm/BCM >> Diagnostic Flow Charts For ECM/Pcm Codes: EO13 To EO69 >> Code EO43, ESC Error Without ESC Module >> Notes
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Code EO43, ESC Error Without ESC Module: Notes

  1. If tapping on engine does not produce a knock signal on "Scan" tester, try tapping the engine closer to the sensor before proceeding.
  2. The ECM supplies a 5-volt reference signal on the 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 the knock sensor is faulty or if the ESC portion of MEM-CAL is faulty.