Exhaust Brake On/Off Switch

266

TM 9-2320-312-24-2

Troubleshooting Section

With OCT01 Software, the exhaust brake can be

When the cruise control on/off switch is on, this

used to apply a parasitic load to the engine in order

parameter provides two special options that allow

to aid engine warm-up. The exhaust brake will help

the exhaust brake to be operated only after the

the engine achieve normal operating temperatures.

driver has depressed the service brake pedal. The

To use this feature, the parameter "Exhaust Brake

two modes of operation that follow are customer

Warm Up Configuration" must be programmed to

programmable:

"Warm Up Only" or "Exhaust Brake & Warm Up".

The "Coast" mode engages the exhaust brake

Also, the on/off switch for the exhaust brake must

be in the ON position and the parameter "Exhaust

when the driver depresses the service brake

Brake Switch" must be programmed to "J1/P1:16"

pedal. The exhaust brake disengages when the

or one of the J1939 options. The "Warm Up Mode

driver releases the service brake pedal.

Idle Speed" parameter must be programmed to an

The "Latch" mode engages the exhaust brake

engine speed between 700 rpm and 1400 rpm. If

the preceding conditions are met, the engine will

when the driver depresses the service brake

ramp up to the engine rpm that is programmed into

pedal. The exhaust brake remains engaged until

the "Warm Up Mode Idle Speed" parameter.

the control detects a change in the control input.

The following actions are examples of a change

Warm up mode will terminate when the engine

in a control input:

reaches normal operating temperatures or when

The throttle is depressed.

one of the following conditions are met:

The clutch pedal is depressed.

The service brake is depressed.

The engine speed drops below 900 rpm.

The clutch pedal is depressed.

The exhaust brake switch is turned off.

The third option for the Exhaust Brake Parameter is

"Manual". The "Manual" mode operates in the same

The vehicle is in gear.

manner regardless of the position of the cruise

control on/off switch. The driver is not required to

The throttle is depressed.

depress the service brake pedal in order to initiate

the exhaust brake. Depress the service brake pedal

The vehicle speed is greater than one mph.

in order to initiate the exhaust brake in the "Latch"

mode and the "Coast" mode.

The ECM detects an excessive load on the

Note: The "Latch" mode and the "Coast" mode are

engine.

customer programmable options. The "Latch" mode

The engine rpm is less than 500 rpm. The engine

and the "Coast" mode determine the operation of

the exhaust brake only when the cruise control

rpm is greater than 1450 rpm.

switch is in the ON position. The "Latch" mode and

the "Coast" mode do not determine the operation

Exhaust Brake On/Off Switch

of the exhaust brake when the engine is active in

cruise control. "Latch" mode and "Coast" mode

An on/off switch can be used to provide operator

require the initiation of the service brake before

control of the exhaust brake in order to inhibit

acting. The action of the service brake disengages

operation during undesirable conditions. Two

the cruise control.

different methods may be used. An in-line switch

can be installed in the output circuit for the exhaust

Note: The output for the exhaust brake is disabled

brake (terminal 12). The switch will turn the brake off

whenever the PTO on/off circuit is on and the

by opening the circuit. This removes power from the

customer parameter "PTO Configuration" is

brake relay. Opening the switch does not disable

programmed to "Cab Switches", "Remote Switches",

the output driver. Opening the switch disables the

or "Remote Throttle".

exhaust brakes.

Warm-up Mode