Wiper Motor Failure

On April 13, 2016, the Office of Defects investigation (ODI) opened this Preliminary Evaluation on 2015-2016 MY Freightliner Cascadia trucks, alleging windshield wiper motor failures. The investigation was opened based on EWR field reports describing windshield wipers that intermittently failed to operate, causing a loss of vision and increasing the risk of a crash. Several of the reports alleged multiple vehicles experiencing the failure, while multiple failures happen on the same vehicle. Many of the field reports indicated the windshield wiper problem was resolved once the wiper motor is replaced.Through communications with the manufacturer, ODI learned they had received 4 complaints, 12 field reports and 1,852 warranty reports involving the alleged defect on the subject vehicles. ODI was also made aware of a crash due to wiper failure during a rain storm. ODI interviewed both the owner and driver of the truck. The driver alleged he switched the wiper speed from intermediate to high and the wiper stopped working. During the loss of vision event, he lost control of his vehicle, hitting an embankment on the passenger side. The owner of the truck stated that after towing the vehicle back to their property, the function of the wipers was tested and they were found not to operate.The manufacturer informed ODI they had collected wiper motors from vehicles that allegedly had wipers fail and bench tested them. In each case they state the motor was found to operate normally. The manufacturer states they have not been able to duplicate the wiper failure problem as described in reports.This investigation has been upgraded to an Engineering Analysis (EA17-001) for ODI to gather additional information concerning wiper system performance. ODI will also study peer vehicles to understand how they perform relative to the subject vehicles.