The control signal to the cab fan (M3) is short circuit to ground.
â–¶ How to fix
Check the control signal cable harness.
What you'll see
No driver-visible symptom recorded.
System reaction
The cab fan will not run.
Diagnostic depth
Detection
The climate control system (E17) has detected that the control signal is stuck at low level, when it should be a PWM signal. The test is performed when the cab fan is running and the starter motor (M1) is not running.
Possible cause
The control signal cable harness is short circuit to ground.