CARRIER ASSEM. 9S8417 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
The engines outlined in this publication contain a strategy which will elevate engine speed in certain conditions. This elevated idle keeps ice from building in the intake manifold. If the charge air cooler outlet temperature remains below −18° C (−0.5° F) for 3 hours, the strategy will engage and the engine speed will be elevate to 1600 rpm. The engine will run at this speed for 20 minutes. After 20 minutes the engine speed will be reduce back to low idle speed.Note: Running at higher engine speeds promotes more NOx Reduction System (NRS) gas flow causing any ice accumulation to thaw.On the current Industrial Engine software, the elevated idle strategy can engage regardless of whether pin 46 is grounded on the "J1" ECM connector. This event can lead to an unexpected increase in engine speed.Solution
Operators should be aware that if the engine is operating in a cold environment, the engine speed may elevate to 1600 rpm. This elevated engine speed can affect operation.A permanent solution from Caterpillar will be available in the next engine software release. The next software will be released by 31March 2015.A new engine software release will correct this functionality to allow the engine speed to elevate only if pin 46 is grounded. Until the new software is available, Caterpillar makes the following recommendations when operating in an environment where the charge air cooler outlet temperature may see sustained operation below −18° C (−0.5° F):
Cover the ATAAC to achieve a charge air cooler outlet temperature greater than −18° C (−0.5° F)
If extended idling is not needed, shut the engine down when operating in extreme cold temperaturesIf you have further questions, consult your Application and Installation engineer.