Diagnostic Aids

WARNING: This page is about a different car, the 1995 Pontiac Trans Sport and 1995 Chevrolet Lumina APV. However, it is still accessible from the selected car via links, so may be relevant.

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