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Emergency Vehicle SCR and DEF Inducement Guidelines 

2010 EPA Engine Emissions Control Requirements 

Roger Lackore 

Mike Power

May 18, 2010

Background 

After extensive consultations with the Environmental Protection Agency (EPA), the Fire 

Apparatus Manufacturers Association (FAMA), the Ambulance Manufacturers Division 

of the National Truck Equipment Manufacturers Association (AMD), and the 

International Association of Fire Chiefs (IAFC), believe we have reached an 

understanding with EPA regarding an approach to Diesel Emission Fluid (DEF) 

inducement strategies for emergency vehicles. Beginning in 2010, routine DEF 

replenishment is considered a critical emission-related engine maintenance requirement 

under EPA regulations; however, engine safety concerns that are particular to emergency 

vehicles permit manufacturers of emergency vehicles to employ less severe vehicle 

inducement measures than those applicable to typical commercial vehicles. 

Inducements perform two functions. One is to ensure that vehicle operators are 

disciplined enough to plan for adequate DEF supply just as they must plan for adequate 

fuel supply. The second function is to ensure any mechanical faults in the emission 

control system are remedied quickly, assuring that any vehicle in service complies with 

EPA emissions standards. This approach will ensure an emergency vehicle that runs low 

on DEF or experiences a mechanical fault is subjected to an inducement sufficient to 

ensure proper SCR system maintenance without undue risk of damage to emergency 

vehicles and without jeopardizing the ability of the vehicle to complete its emergency 

response mission. 

Inducements for Emergency Vehicles 

After consultations with EPA, we believe that the following inducement strategies for 

emergency vehicles that are aligned to the function these vehicles perform and the critical 

nature of their use for public safety will meet requirements for ensuring that scheduled 

maintenance is performed in use. The inducement strategy should adhere to the 

following criteria: 

1. Emergency vehicles will employ graduated driver warning signals previously 

established by engine manufacturers with respect to SCR systems. 

2. Emergency vehicles will employ an “initial” driver inducement that limits the 

vehicle speed to 55 mph. 

3. Emergency vehicles will employ a “last resort” driver inducement that limits 

vehicle speed to 25 mph. This speed limitation will be sufficiently onerous to 

induce emergency vehicle operators to perform the required maintenance quickly, 
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but still allow them to transport a patient or reach the scene of an emergency, 

albeit at a significantly reduced speed. 

4. Inducements for emergency vehicles will not be required to limit engine torque. 

This will avoid the situation where an emergency vehicle would be unable to 

climb a grade that it can normally ascend. 

5. Fire apparatus inducements may be postponed while the apparatus is operating in 

PTO mode. If the apparatus drops out of PTO mode to reposition, the 25 mph 

limit may be employed, but may be discontinued temporarily prior to the engine 

being shut off. This will assure that essential functions such as pumping operation 

or aerial operation can continue uninterrupted while fighting a fire or conducting 

other operations at the scene of an emergency. 

6. At the conclusion of the emergency event, the “last resort” inducement (25 mph 

speed limit) and well as cessation of PTO operation will be employed and will 

continue until DEF has been added. 

FAMA Believes That These Inducement Strategies Will Meet the EPA Emissions 

Regulations 

Strategies 1 and 2 fit with the general industry inducement strategies employed by onhighway vehicles to meet 2010 emissions standards using selective catalytic reduction 

technologies. Although the 25 mph “last resort” vehicle speed limitation is higher than 

the typical level of 5 mph employed for commercial vehicles, this limit in conjunction 

with the a limit on PTO operation is sufficiently onerous to induce emergency vehicle 

operators and fleet managers to take immediate action to maintain an effective SCR 

system. Any emergency vehicle limited to a top speed of 25 mph will represent a 

significant liability to the fire fighting or care provider organization. Any organization 

that does not either remedy the situation or remove the vehicle from service at the earliest 

safe opportunity would be vulnerable to serious legal liability claims. 

Inducement strategies 4 and 5 are provisions that are meant to mitigate risk of damage to 

the vehicle engaged in emergency operations. In addition these provisions mitigate the 

risk of harm to the vehicle operator and the public. These strategies are allowed under 

EPA regulations since protection from vehicle damage is one of the allowed uses of 

Auxiliary Emissions Control Devices as prescribed by the definition of a defeat device in 

40CFR 86.004-2. 

The nature of fire fighting often requires the apparatus be placed close to structure fires, 

or in the path of wild fires. Shifts in wind or other changes in the situation will require 

the apparatus to be moved quickly to protect the vehicle against damage. This damage 

can result from heat or open flame, or may be caused by the ingestion of excessive 

amounts of soot or burning embers into the engine. 

Inducement strategy 4 ensures that an apparatus operator attempting to move the vehicle 

away from rapidly approaching flames will be able to do so. Engine torque derates could 

prevent the apparatus from ascending a grade at any speed and approaching flames, heat, 

or soot could envelope and damage a vehicle without sufficient engine torque to escape. 
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Inducement strategy 5 ensures a fire fighting vehicle may continue to perform fire 

suppression operations in close proximity to an approaching fire, or eminent structure 

collapse. Rapid repositioning and subsequent re-engagement of the pumping function 

during an emergency event is necessary to move the vehicle out of harms way, while 

permitting the vehicle operator to continue suppression operations to protect the vehicle 

from damage consistent with EPA regulations. 

Emergency Vehicle Definition 

These inducement strategies may only apply to emergency vehicles. EPA will require 

engine OEM’s to demonstrate to EPA that these strategies will only be available to 

vehicles that meet the limited definition of emergency vehicle – to include automotive 

fire apparatus, wildland fire apparatus, or ambulances meeting one of the following 

criteria: 

1. Fire apparatus shall meet the scope and application of National Fire Protection 

1901 Standard for Automotive Fire Apparatus – 2009 Edition and shall conform 

to one of the following definitions as found in that standard: Pumper Apparatus; 

Initial Attack Apparatus; Mobile Water Supply Apparatus; Aerial Fire Apparatus; 

Quint Fire Apparatus; Special Service Fire Apparatus; or Mobile Foam Fire 

Apparatus. 

2. Wildland fire apparatus shall meet the scope and application of NFPA 1906 

Standard for Wildland Fire Apparatus – 2006 Edition and shall conform to 

wildland fire apparatus definition found in that standard. 

3. Ambulances shall meet the scope and definition of General Services 

Administration KKK-A-1822F “Federal Specification for the Star of Life 

Ambulance” and shall conform to one of the following definitions: Type I 

Ambulance; Type I - AD (Additional Duty) Ambulance; Type II Ambulance; 

Type III Ambulance; or Type III - AD (Additional Duty) Ambulance. 

General Inducement Strategies 

The following tables describe general strategies appropriate for emergency vehicles, 

reflecting the revised emergency vehicle inducements. Fluid levels are provided only as 

general guidelines. The specific progression of lamp colors and flash patterns is 

determined by the engine OEM and described to the EPA. 

DEF Keep-Fill Inducement Strategy 

Condition Warning Lamps Inducement 

Fluid Level Above 10% None None 

Fluid Level 5% to 10% First Warning Lamp None 

Fluid Level below 5% Additional Lamp Actions 55 mph Speed Limit 

DEF Tank Empty Additional Lamp Actions 55 mph Speed Limit 

Tank empty and ignored 

after one of the following 

events: refueling, parking or 

restart.* 

Additional Lamp Actions 25 mph Speed Limit and 

no PTO operation after 

emergency event 

Inducement mode is exited by adding DEF to the tank. 
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DEF Quality Inducement Strategy 

Condition Warning Lamps Inducement 

Incorrect DEF Fluid 

Detected 

First Warning Lamp None 

Engine has run for several 

hours after detection 

Additional Lamp Actions 55 mph Speed Limit 

Engine has run for many 

hours after detection and 

after one of the following 

events: refueling, parking or 

restart.* 

Additional Lamp Actions 25 mph Speed Limit and 

no PTO operation after 

emergency event 

Inducement mode is exited by replacing fluid with proper DEF 

SCR Fault Inducement Strategy 

Condition Warning Lamps Inducement 

SCR Fault Detected First Warning Lamp None 

Engine has run for several 

hours after detection 

Additional Lamp Actions 55 mph Speed Limit 

Engine has run for many 

hours after detection and 

after one of the following 

events: refueling, parking or 

restart.* 

Additional Lamp Actions 25 mph Speed Limit and 

no PTO operation after 

emergency event 

Inducement mode is exited by repairing the cause of the fault 

*The inducement strategy should use one of these trigger events (refueling, parking, or 

restart). 

Engine OEM Reporting 

Details of the exact inducement strategy must be presented by each engine OEM and 

approved the EPA. The EPA will expect to be provided with answers to the following 

questions: 

 What is the exact inducement strategy for emergency vehicles? 

o How is each inducement entered? 

o How is each inducement exited? 

 What control does the OEM have in place to ensure that engines with emergency 

vehicle inducement strategies are sold only for use in emergency vehicles? 

For questions regarding this document contact: 

Roger Lackore 

FAMA Chassis Technical Committee Chair 

920 832 3249 

rlackore@piercemfg.com