Diagnostic Aids
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.