TM 5-3805-280-24-1
Tests
IMPORTANT: Retainer tab on male half of wiring
harness connector halves must be
pushed down before pulling halves
apart. Never pull on wiring leads
2. Push retainer tab down then pull connector halves
apart.
3. Measure resistance between the ground (A) and power
(C) terminals of EC sensor. If resistance is to
specification, go to next step. If resistance is not as
specified, replace EC sensor.
Engine Control (EC) Sensor--Specification
Resistance ....................................................... 2000 400 ohms between
ground and power terminals
NOTE: EC sensor is on the inside of EC motor housing.
4. When using a volt meter, install test harness in series
with wiring harness for EC sensor (E). Connect volt
meter.
When using the laptop computer with excavator
diagnostics program, select "2 EC angle" from the
Monitor Data Items. (See the installation procedure in
this group.)
9025
25
49
5. Turn the engine rpm dial to the slow idle position.
6. Turn key switch ON. EC motor (D) goes to the slow
idle position.
7. Turn engine rpm dial to fast idle, push E mode switch,
push auto-idle switch then wait 4 seconds, and then
turn engine rpm dial to slow idle. EC motor must move
to each position. Record voltage reading for each
mode.
Fast Idle in Standard Mode--Specification
Voltage....................................................................... 3.3--3.7 volts typical
E (Economy) Mode--Specification
Voltage....................................................................... 3.0--3.3 volts typical
Continued on next page
TX,9025,GG2710 1913AUG982/3
6-180
