Code 43 - Electronic Spark Control

Code No. 43 will set if circuit No. 26 becomes open or shorted and voltage goes above 3.5 volts or falls below 1.5 volts. This condition must exist for approximately .6 second before code will be set. Code will also be set if knock sensor produces a signal longer than 3.67 seconds during a 3.9 period. Under both conditions, the coolant temperature must be greater than 122°F (50°C) and engine speed between 1000 and 5800 RPM.

Fig 1: Flow Chart - Code 43, Electronic Spark Control

Courtesy of ISUZU MOTOR CO.