Diagnostic Aids

1993 Chevrolet Sportvan G20, 5.7 KSECTION Diagnostic Aids

Code 43 can be caused by a faulty knock sensor connection at ESC module or ECM. Also, check controller-to-ECM signal line for an open or short to ground.

CODE 43 ECM TERMINAL & CIRCUIT WIRING IDENTIFICATION

Application ECM Terminal Wire Color
All With 4L60-E Transmission Knock Signal B15 Dark Blue
All With 4L80-E Transmission Knock Signal D5 Dark Blue
Fig 1: CODE 43, Schematic, ESC W/ Spark Control Module
G92J21765
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.