SECTION 3 - CHASSIS & TURNTABLE
3-148
– JLG Lift –
3121290
DTC 642- 5 Volt External Low Voltage
• Engine Control Module.
• Check Condition- Key on.
• Fault Condition- ECM 5-volt output is below the acceptable
limit.
• Corrective Action(s)- Illuminate MIL and/or sound audible
warning or illuminate secondary warning lamp.
• Non-emissions related fault.
The ECM supplies 5-volt power to sensors, switches, and actu-
ators external to the ECM. By supplying the power to these
devices, the ECM can accurately measure their output relative
to its own ground reference. The ECM can also control when
the devices are active and put the devices in a low or no power
state based on the current operating condition of the engine
or vehicle.
If this fault sets, something other than the ECM is drawing ECM
5-volt power output below an acceptable threshold. This may
be due to a short in wire harness, malfunctioning device, or
ECM power output circuitry failure.
Diagnostic Aids
• Measure ECM 5-volt output while cycling key on with
engine stopped. Verify output is lower than fault thresh-
olds configured in diagnostic calibration.
• Inspect 5-Volt output circuit in wire harness and look for
shorts to ground or other harness circuits.
• Disconnect each device powered by the ECM 5-volt output
one-at-a-time. Powered devices may include throttle actu-
ator, smart sensors, smart actuators, etc. After disconnect-
ing device, observe system fault and determine if fault has
cleared. If fault clears, troubleshoot disconnected device
for failures.
• With all 5-volt powered devices disconnected, look for a
change in fault state and measure ECM 5-volt output. Verify
it is within acceptable limits.
E
le
c
tro
n
ic
T
h
ro
ttle
A
c
tua
to
r w
/S
e
ria
l
P
o
s
itio
n
F
e
e
d
b
a
c
k
2
1
6
1
3
1
2
1
5
V
_
e
x
t
V
s
=
+
5
V
D
C
5
V
_
rtn
T
P
S
1
T
P
S
S
E
R
+
+
-M
o
to
r
D
B
W
-
D
B
W
+
E
C
M
H
-B
rid
g
e
1
9
T
P
S
S
E
R
-
S
e
ria
l
x
m
itte
r
Electronic Throttle
Actuator w/Serial
Position Feedback
2
16
13
12
1
5V_ext
Vs=+5 VDC
5V_rtn
TPS1
TPS SER +
+
-
Motor
DBW-
DBW+
ECM
H-Bridge
19
TPS SER -
Serial
xmitter
Summary of Contents for 450A II Series
Page 46: ...SECTION 3 CHASSIS TURNTABLE 3 6 JLG Lift 3121290 Figure 3 4 Drive Hub 4WD Front Only ...
Page 79: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 39 Figure 3 32 Swing Bearing Drive ...
Page 101: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 61 Figure 3 42 Auxiliary Pump ...
Page 113: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 73 Figure 3 53 EMR2 Fault Codes Sheet 1 of 5 ...
Page 114: ...SECTION 3 CHASSIS TURNTABLE 3 74 JLG Lift 3121290 Figure 3 54 EMR2 Fault Codes Sheet 2 of 5 ...
Page 115: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 75 Figure 3 55 EMR2 Fault Codes Sheet 3 of 5 ...
Page 116: ...SECTION 3 CHASSIS TURNTABLE 3 76 JLG Lift 3121290 Figure 3 56 EMR2 Fault Codes Sheet 4 of 5 ...
Page 117: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 77 Figure 3 57 EMR2 Fault Codes Sheet 5 of 5 ...
Page 159: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 119 ...
Page 161: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 121 ...
Page 163: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 123 ...
Page 165: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 125 ...
Page 173: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 133 Sensor Transducer Type ...
Page 177: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 137 Sensor Transducer Type ...
Page 179: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 139 ...
Page 181: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 141 ...
Page 183: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 143 ...
Page 185: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 145 ...
Page 187: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 147 ...
Page 203: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 163 ...
Page 207: ...SECTION 3 CHASSIS TURNTABLE 3121290 JLG Lift 3 167 ...
Page 217: ...SECTION 4 BOOM PLATFORM 3121290 JLG Lift 4 5 Figure 4 2 Boom Limit Switches ...
Page 310: ...SECTION 5 HYDRAULICS 5 70 JLG Lift 3121290 NOTES ...
Page 312: ...SECTION 6 JLG CONTROL SYSTEM 6 2 JLG Lift 3121290 Figure 6 2 Controller Block Diagram 0 ...
Page 370: ...SECTION 6 JLG CONTROL SYSTEM 6 60 JLG Lift 3121290 NOTES ...
Page 394: ...SECTION 7 BASIC ELECTRICAL INFORMATION SCHEMATICS 7 24 JLG Lift 3121290 NOTES ...
Page 395: ......