User's Manual

ManualsBrandsBENDIX ManualsElectronic TreadlesBENDIX SD-15-4111

SD-15-4111

MOUNTING

PLATE

FIGURE 3 - OUTPUT VOLTAGE

OPEN THROTTLE

(FULL)

ET-S

™

TREADLE

OUTPUT

VOLTAGE

ENGINE

MAX

RPM

IDLE

CLOSED THROTTLE

(OPEN)

MOUNTING

PLATE

POTENTIOMETER

CONNECTOR

FIGURE 1 - ET-S

™

AND ET-S2

™

ELECTRONIC TREADLES

CATERPILLAR

CUMMINS

DETROIT

DIESEL

DESCRIPTION

The ET-S

™

and ET-S2

™

treadles are engine compartment

bulkhead mounted electronic treadles. On electronically

controlled diesel engines, the electronic treadle fulfills the

same function as a conventional mechanical throttle.

However, rather than transmitting a mechanical force to the

engine governor, the electronic treadle controls engine speed

by supplying a variable electrical voltage to the engine’s

electronic controller.

The main components of the ET-S

™

and ET-S2

™

treadles

are: a mounting plate, suspended treadle, potentiometer

(variable resistor), actuator body and base. The selected

potentiometer, chosen for a specific engine application,

provides the electrical link to the engine control system.

OPERATION

The electronic treadles provide smooth, graduated throttle

control through the function of its potentiometer (variable

resistor). The drive shaft of the cam follower assembly

transfers any movement of the treadle to the potentiometer.

ACTUATOR BASE

TREADLE

Bendix

ET- S

™

& ET-S2

™

Suspended Electronic Treadle

ACTUATOR BODY

DETROIT CATERPILLAR CUMMINS

DIESEL

CLOSED

THROTTLE 7 - 18% 10 - 20% 5 - 17%

IDLE (OPEN)

OPEN

THROTTLE 74 - 90% 75 - 90% 70 - 81%

(FULL)

FIGURE 2 - OUTPUT VOLTAGE, AS A PERCENTAGE OF

SUPPLY VOLTAGE

ET-S2

™

TREADLE

TREADLE PIVOT PIN

MOUNTING

PLATE

POTENTIOMETER

ET-S

™

TREADLE

Summary of content (8 pages)

PAGE 1
SD-15-4111 ® Bendix® ET- S™ & ET-S2™ Suspended Electronic Treadle TREADLE POTENTIOMETER MOUNTING PLATE ACTUATOR BODY MOUNTING PLATE TREADLE PIVOT PIN ACTUATOR BASE CONNECTOR TREADLE TREADLE POTENTIOMETER ET-S™ TREADLE MOUNTING PLATE ET-S2™ TREADLE FIGURE 1 - ET-S™ AND ET-S2™ ELECTRONIC TREADLES The ET-S™ and ET-S2™ treadles are engine compartment bulkhead mounted electronic treadles.
PAGE 2
As the potentiometer rotates, its resistance changes. This way, the potentiometer can react to the driver’s request for engine power through the ET-S™ or ET-S2™ treadle by changing resistance. The resulting change of voltage is sensed by the electronic engine controller. The electronic treadle receives its supply voltage from the engine control unit. If the driver does not request engine power, the treadle is in the idle position. This condition is also referred to as “Closed Throttle.
PAGE 3
ACTUATOR BASE MOUNTING PLATE 1 POTENTIOMETER 2 #10 SCREWS 3 RETAINING RING 4 NYLON WASHER ACTUATOR BODY TREADLE ARM ET-S™ TREADLE TREADLE 5 REPLACEABLE RUBBER COVER (ET-S™ TREADLE ONLY) 6 NYLINER BEARING 7 SPRING PIVOT PIN PIVOT PIN 6 NYLINER BEARING TREADLE ARM TREADLE 4 NYLON WASHER 3 RETAINING RING 7 SPRING ET-S2™ TREADLE FIGURE 5 - ET-S™ AND ET-S2™ TREADLE EXPLODED LINE DRAWING All other repairs require replacement of the ET-S™ or ET-S2™ treadle.
PAGE 4
3. Inspect the cable assembly for loose or frayed wires, physical damage, or any contaminants on the connectors. Replace as necessary. ASSEMBLY 1. Securely clamp the treadle mounting plate. 2. (a) For Detroit Diesel Potentiometers: Align the drive slot, and engage the potentiometer the drive tang at the end of the drive shaft (see Figure 4). Rotate the potentiometer clockwise until the first set of mounting holes align. Secure using two screws: torque to 25 (±5) in. lbs.
PAGE 5
Closed Throttle (open) Range: 5-17% DIODES IDLE VALIDATION SWITCH IVS PIN 6 TEST LOAD 470 OHM TEST LOAD 470 OHM PIN 2 Open Throttle (full) Range: 70-81% LOCK TAB V3 (LOGIC HIGH AT IDLE) POTENTIOMETER SET VOLTAGE AND PC. NO. SHOWN HERE V2 (LOGIC LOW AT IDLE) PIN 1 IVS GROUND Vs SUPPLY VOLTAGE PIN 5 PEDAL POSITION SENSOR Vs SUPPLY VOLTAGE PIN 3 .
PAGE 6
b. Connect the potentiometer or position sensor to the volt meter and power supply as shown in Figures 6, 7 or 8, depending on the model. Note: The power supply needs to be 5 VDC. Do not exceed this voltage. 4. Insert the pivot pin from the potentiometer side of the ET-S2™ treadle assembly through the treadle, treadle arm, nyliner bearing (6) and spring (7). Secure with the nylon washer (4) and retaining ring (3). c.
PAGE 7
8. Use only genuine Bendix ® replacement parts, components and kits. Replacement hardware, tubing, hose, fittings, etc. must be of equivalent size, type and strength as original equipment and be designed specifically for such applications and systems. 9. Components with stripped threads or damaged parts should be replaced rather than repaired. Do not attempt repairs requiring machining or welding unless specifically stated and approved by the vehicle and component manufacturer. 10.