C.E. Niehoff & Co. EPM Troubleshooting Guides - Manual (Page 5)

Page 5
TG0051A
Section D: Troubleshooting the EPM
Pin Function
TABLE 4 – EPM Harness Plug
Socket Functions
A
B
C
D
Battery Ground
Alternator Phase Signal
Energize (Active Low) Signal
Ignition Signal
Figure 5 – EPM System Schematic
EPM Electric Power Manager
DESCRIPTION AND OPERATION
Main diagnostic feature of the EPM is a green LED
located on the top of the device. The EPM connects and
disconnects batteries based on operational requirements.
EPM also allows batteryless operation until vehicle is
shut off.
Figure 4 – EPM Electric Power Manager
T
J1939
Connector
Under Cap
(see p. 3 for
details)
T
EPM LED
T
EPM
Connector
T
AUX
Circuits
Connector
T
Aux. Load
Diagnostic
LEDs
EPM LED COLOR EPM STATUS
TABLE 3 – EPM LED Diagnostics
EPM is not energized or EPM is
defective.
Off (Clear)
Flashing GREEN
Steady GREEN
Batteries connected for 3 minutes
for engine starting after battery
connect switch pressed.
Normal operation (batteries are
connected to the system and
engine is running)
Pin
Function
(Max. 30 A)
TABLE 5 – AUX Circuit and LED Functions
A
B
C
D
E
14 V
28 V
28 V
28 V
28 V
EPM
EPM
EPM
LED Color
Normally On
If LED
OFF:
GREEN
GREEN
GREEN
GREEN
GREEN A short or overcurrent
may have occurred.
Check AUX load wiring
and reset EPM by
pressing battery
connect switch
BATTERY CONNECT SWITCH