APPENDIX H -- INPUT/OUTPUT FUNCTIONS - TM-9-2320-303-24-10348

WTEC III ELECTRONIC CONTROLS TROUBLESHOOTING MANUAL

APPENDIX H -- INPUT/OUTPUT FUNCTIONS

These schematics show the intended use of the specified controls features which

have been validated in the configuration shown. Any miswiring or use of these

features which differs from that shown could result in damage to equipment or

WARNING!

property, personal injury, or loss of life. ALLISON TRANSMISSION IS NOT

LIABLE FOR THE CONSEQUENCES ASSOCIATED WITH MISWIRING

OR UNINTENDED USE OF THESE FEATURES.

H. ENGINE BRAKE/PRESELECT REQUEST AND ENGINE BRAKE ENABLE

(EXHAUST BRAKE OPTIONAL)

USES: Used with engine brakes controlled by electronic engines to signal the ECU that the brake is active and to

provide increased braking by preselecting a lower range. Also prevents engagement of engine brake with

throttle > 0 or lockup OFF.

VARIABLES TO SPECIFY: Preselect range. Standard value is second range.

VOCATIONS: Various

Exhaust brake high side driver maximum

current per engine manufacturer

ECM

ENGINE BRAKE

DASH SWITCH

One or

the other

WIRE 132

V-3

NOTE: If the engine brake is an inductive load,

ENGINE BRAKE

it must be diode suppressed.

ENGINE BRAKE

ENABLE OUPUT

DASH SWITCH

OPTIONAL

CUSTOMER-FURNISHED

ECU

VIW CONNECTOR(S)

WIRE 119

S-11

ENGINE

ENGINE BRAKE AND

COM

DASH

BRAKE

PRESELECT REQUEST

LIGHT

SOLENOID

(Optional)

VIM

Relay shown de-energized

SWITCHED

POWER

V05940

Figure H4. Engine Brake/Preselect Request and Engine Brake Enable (Exhaust Brake -- Optional)

0021 00176