Clean Idle Engines; Transmission Identification - Mack Granite GU Series Operator's Handbook Manual

Clean Idle Engines

The California Air Resources Board (ARB) requires that 2008 and later model
year vehicles be equipped with engines having tamper-resistant software
which limits the time at which the engine can idle at speeds above low idle
(550–700 rpm). At speeds above low idle, and without a PTO engaged, idle
time will be limited to five minutes, after which the engine will revert back to low
idle. Vehicles equipped with a Clean Idle engine are identified by a label which
is affixed to the left front corner of the hood on conventional models (GU).

Transmission Identification

The MACK T300 Series transmission serial number is located on the rear
left side of the main case.
Clean Idle Engine Label
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