Programming – Idle Shutdown Timer

The Idle Shutdown Timer is designed to shut down the engine after a specified idle period. For the shutdown to occur, certain conditions must be met for the entire time-out period. These conditions include: no load on the engine, cold mode inactive and vehicle speed must be 0 (zero) mph.

If these conditions are met, then 90 seconds before the customer specified idle time is reached, the check engine light will start flashing at a rapid rate. If either the brake or clutch pedals are depressed during this final 90 seconds when the lamp is flashing, the idle shutdown timer will be disabled, if the Idle Shutdown Override parameter is programmed to Yes. This allows the driver to override the idle shutdown timer if necessary to keep the truck idling.

If the idle shutdown timer is overridden, the ECM will log the override as a Logged Event. These Logged Events can be viewed with a service tool.

If the timer is set to 0 (zero), the Idle Shutdown feature is turned off.

If the truck/engine is wired for PTO use, the Idle Shutdown Timer will not be active when PTO mode is active. In this case PTO shutdown time would be used for the shutdown time. It is important that the engine/truck be wired for PTO, since if it is not, the engine could shutdown after the idle shutdown time while in PTO mode

All electronically controlled on-highway engines covered in this handbook.


The idle shutdown timer has several advantages. One is that it encourages drivers to shut the engine off before leaving the truck for an extended period of time.

The other advantages include the ability to limit unnecessary idle time, save fuel and reduce engine wear.

When the engine shuts down as a result of the Idle Shutdown Timer the truck’s dash remains “hot”. To avoid draining the batteries the ignition key must be switched to the “off” position after the engine shuts down.

Caterpillar recommends that this parameter be set in the 3 to 5 minute range for most operation.
Check with the truck manufacturer as to the availability of the optional wiring to shut the trucks electrical system off after an Idle Shutdown event.


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