Diagnostic Aids
Code 43 can be caused by a faulty connection at the knock sensor, at the ESC module or at the control module. Check the controller-to-control module signal line for an open or short to ground. Check for poor connections or 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 or damaged harness. If connections and harness check out 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 the malfunction.