Diagnostic Aids

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

Fig 1: Code 43 Schematic (3.1L FWD Van) Knock Sensor With Spark Control Module

Fig 2: Code 43 Flow Chart (3.1L FWD Van) Knock Sensor With Spark Control Module