Scania fault code 4171

Code 4171 is used by 3 different Scania systems. Choose the control unit shown in your diagnostic tool:

EMS Engine Management System SCR – Nitrogen oxides (NOx) downstream of the catalytic converter The quantity of nitrogen oxides measured differs from what it should be. Read explanation → EMU Heater H39, main transistor, electrical fault The control system has measured current of over 500 mA while the PWM signal to both batteries is low. Read explanation → DDU Tweeter on right-hand A-pillar panel, short circuit to earth The DDU control unit interprets a short circuit to earth for the tweeter on the right-hand A-pillar panel. Read explanation →