October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Diagnostic Aids

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

CODE 43 ECM TERMINAL & CIRCUIT WIRING IDENTIFICATION

Application	ECM Terminal	Wire Color
All With 4L60-E Transmission Knock Signal	B15	Dark Blue
All With 4L80-E Transmission Knock Signal	D5	Dark Blue

Fig 1: CODE 43, Schematic, ESC W/ Spark Control Module

Fig 2: CODE 43, Flowchart, ESC W/ Spark Control Module