Engine RPM's surging during pumping mode

What NHTSA is examining

On January 10, 2011 the Office of Defects Investigations (ODI) opened a Preliminary Evaluation (PE11-001) based on a Product Improvement Program (PIP) (ODI TSB #10036912) submitted by Caterpillar dated August 18, 2010.The PIP was intended to address engine RPMs that could surge while the fire fighting vehicle was in a water pumping mode.This engine surge could cause significant fluctuations in water pressure being directed onto a fire through a hose.The bulletin states that this condition in conjunction with other factors or circumstances could result in a risk of personal injury or death.Caterpillar's PIP provided information involving the installation of new engine software on certain fire trucks with C9 engines.On June 27, 2011 ODI upgraded its investigation to an Engineering Analysis.No information request (IR) letter was sent to Pierce, instead a field inspection of a Pierce fire truck was conducted.In August 2011 representatives from ODI, the Vehicle Research and Test Center and Pierce conducted an on-site fire truck performance inspection of a complaint vehicle in Sherwood, Arizona.The purpose was to jointly inspect a complaint vehicle that was recently outfitted with updated engine software.The Sherwood fire truck engine was started and remained idling while the fire truck was set in water pumping mode.The representatives were able to witness the effects of the new software with regards to engine surge and verified that the alleged defect did not exist during this…

Vehicles under investigation