We had the same problem and, in frustration, replaced the entire pump assembly. Upon examination of the old pump, we removed the motor from the intake filter (three screws) and noticed that the impeller had moved away from the motor armature by approximately 3/16th of an inch. This space between the motor and impeller caused the pump to cavitate, loose suction resulting in the suds routine and other drain errors. We pushed the impeller firmly back into the armature and found that the old pump worked properly. Our machine is 11 years old and we don't know why the impeller shaft would move nor do we know if the impeller will now stay in it's correct position. Anyway, we now have an extra pump assembly! Tip: when reassembling the motor to the filter housing, apply a little silicone grease to the o-ring - this makes reassembly a snap!