A first fuel value (FL_Signal) indicative of the quantity of fuel presently in a fuel tank (34) and a second fuel value (FL_LOW_THLD) representing a quantity of fuel in the tank at which a maximum Injection Control Pressure (ICP) limit should be changed are processed by a processor (22). When the result of the processing discloses that the second fuel value is less than the first fuel value, the maximum ICP limit is reduced from a greater value (ICPC_NORMAL_LMX) to a lesser value (ICPC_FL_LMX).