Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1992 Pontiac Firebird, 1992 Oldsmobile Custom Cruiser, 1992 Chevrolet Caprice, 1992 Chevrolet Camaro, and 1992 Cadillac Brougham. However, it is still accessible from the selected car via links, so may be relevant.
Code 43 can be caused by a faulty connection at knock sensor, ESC module or control module. Check controller-to-control module signal line for an open or short to ground. Check for poor connections and damaged harness. Inspect control module harness connectors for backed-out sensor signal and ECM input signal terminals, improper mating, broken locks, improperly formed or damaged terminals and damaged harness. If connections and harness are okay, monitor knock signal parameter using "Scan" tester while moving related connectors and wiring harness. If failure is induced, knock signal will abruptly change. This may help to isolate malfunction.