diff --git a/Firmware/fsensor.cpp b/Firmware/fsensor.cpp
index 34fab48f..8800dbb0 100644
--- a/Firmware/fsensor.cpp
+++ b/Firmware/fsensor.cpp
@@ -430,6 +430,11 @@ void fsensor_st_block_chunk(block_t* bl, int cnt)
 	}
 }
 
+//! update (perform M600 on filament runout)
+//!
+//! Works only if filament sensor is enabled.
+//! When the filament sensor error count is larger then FSENSOR_ERR_MAX, pauses print, tries to move filament back and forth.
+//! If there is still no plausible signal from filament sensor plans M600 (Filament change).
 void fsensor_update(void)
 {
 	if (fsensor_enabled)
@@ -452,19 +457,6 @@ void fsensor_update(void)
 			fsensor_err_cnt = 0;
 			fsensor_oq_meassure_start(0);
 
-//			st_synchronize();
-//			for (int axis = X_AXIS; axis <= E_AXIS; axis++)
-//				current_position[axis] = st_get_position_mm(axis);
-/*
-			current_position[E_AXIS] -= 3;
-			plan_buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], 200 / 60, active_extruder);
-			st_synchronize();
-
-			current_position[E_AXIS] += 3;
-			plan_buffer_line(current_position[X_AXIS], current_position[Y_AXIS], current_position[Z_AXIS], current_position[E_AXIS], 200 / 60, active_extruder);
-			st_synchronize();
-*/
-
 			enquecommand_front_P((PSTR("G1 E-3 F200")));
 			process_commands();
 			cmdqueue_pop_front();
diff --git a/Firmware/fsensor.h b/Firmware/fsensor.h
index df58def2..0b262a51 100644
--- a/Firmware/fsensor.h
+++ b/Firmware/fsensor.h
@@ -27,7 +27,6 @@ extern void fsensor_disable(void);
 extern bool fsensor_autoload_enabled;
 extern void fsensor_autoload_set(bool State);
 
-//update (perform M600 on filament runout)
 extern void fsensor_update(void);
 
 //setup pin-change interrupt