Pierce Enforcer Operator'S Manual Download

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Engine Exhaust After Treatment Systems / 5-31

OPERATION

Upon completion of parked regeneration, the following should occur:
1. The HEST light will remain illuminated until the exhaust outlet temperature is below the temperature threshold

or the vehicle speed exceeds 5 mph.

2. The DPF light will turn off, along with all other associated warning lights. If the Check Engine light, Stop Engine

light or MIL are still illuminated, a fault condition exists that should be diagnosed by a Detroit service
representative.

Parked regeneration is not allowed when the DPF light is not illuminated.

5-13.4a Canceling Stationary Regeneration

If it is necessary to interrupt a stationary/parked regeneration before completion (such as in order to respond to an
emergency call), the driver can toggle the regeneration switch to ON for five seconds, The DPF light will flash on for
one second to show acceptance of the cancellation request and then return to idle. Turning the ignition off, placing
the transmission in gear, or releasing the parking brake will also cancel the regeneration.
If a parked regeneration is interrupted, the DPF light will illuminate, indicating the need for further regeneration. The
DPF light will remain illuminated until the regeneration is completed through either automatic regeneration (by
driving or pumping) or by resuming a parked regeneration.

5-13.5 Regeneration Inhibit

The Regeneration Inhibit Switch can be used to temporarily suspend an in-process active regeneration. This may
be done when the regeneration is going to occur in a location or situation that is not ideal and must be postponed.

An indicator will appear on the dash panel when this mode is activated.

•

The regen inhibit switch should not be used for normal operation. It should only be used for hazardous
environments.

•

Overuse of the regeneration inhibit feature

will

lead to more frequent need of parked/stationary regeneration,

or the need for servicing and/or replacing the Diesel Particulate Filter (DPF).

5-13.5a Regeneration Inhibit While Pumping

A common misconception is that regeneration will negatively affect pumping operations. Any time the engine detects

a need for regeneration, it is looking for conditions (such as engine speed and temperature) to start an active
regeneration. If the pump is engaged, the regeneration process should not affect the engine speed.

5-13.6 Maintenance

Regeneration removes soot from the DPF, but accumulated ash remains in the filter. Over time the DPF must be
removed, disassembled, and cleaned in a special machine to remove the ash build-up.
•

CEL will illuminate and a fault code will be set when ash removal is necessary.

•

The maintenance interval for Detroit engines could be up to 300,000-400,000 miles, or between 9,000 and
10,250 hours, which is dependent on duty cycle, type of oil used, and oil consumption rate.

•

Using CES20081/API CJ-4 oil will maximize the DPF maintenance interval.

Inhibiting or suspending regeneration too frequently can result in exhaust restriction, higher fuel
consumption, and engine performance loss due to soot build-up in the DPF.
If the DPF has reached system limits (DPF light flashes with Check Engine Light) the operator needs to
take action such as removing the truck from a high-load mission, and initiating an active regeneration
or a parked regeneration.