
152 KENR8601
Troubleshooting Section
Te st Step 6. CHECK THE BTB+ OUTPUT
CIRCUIT
A. Stop the engine.
B. Disconnect three terminal connector J1 on the
BTB+.
C. Measure t he resistance from pin A to p in B of J1.
Expected Result:
The resistance should be 14.6 ohms ± 3.0 ohms.
Results:
•
OK – The resistance is correct. There may be an
intermittent problem.
Repair: The system may need to be reset. Shut
down t he system by turning the E C S to the
OFF/RESET position. Then, restart the genset and
verify that the genset is operating properly. Watch
the genset for any recurrence of the problem.
STOP.
•
NOT OK – The resistance is not correct. The
BTB+ is faulty.
Repair: The BTB+ has failed. Replace the BTB+.
Refer to Testing and Adjusting, “EM CP Electronic
Control (Bus Transformer Box) - Replace”
STOP.
i02891659
GSC CID 1170 - FMI 04
SMCS Code: 1409-035
Conditions Which Generate This Code:
The Bus Transformer Box (BTB +) reduces the AC
line to neutral voltages of phase A and phase C from
the bus to usable signal levels for the GSC+P. The
GSC+P uses these reduced signals for detecting
the phase sequence of the bus. The GSC+P will
utilize the signal of phase A in orde r to m ea sure the
amplitude of the voltage on the bus. The GSC+P will
utilize the signal of phase C in order to measure the
frequency of the voltage on the bus.
The possible cause of CID 1170 FMI 04 diagnostic
code is an open neutral connection to the input of the
BTB +. An open neutral will cause a phase angle of
approximately 180°.
Tes t Step 1. CHECK THE VOLTAGE
OF THE INPUTS TO THE BUS
TRANSFORMER BOX (BTB +)
g00603288
Illustrat
ion 80
Bus transformer box
A. Turn the Engine Control Switch (ECS) to “STOP”.
B. Locate the
input wires of the BTB +.
C. Start the engine and run the engine at rated speed.
D. Close the breaker in order to energize the bus.
E. Meas ure th
e voltage from phase A to the neutral
lead. Also, measure the voltage from phase C to
the neutral lead. Record the voltage readings.
F. Measure the voltage from Phase A to Phase B.
G. Compare th
e voltages measured in the previous
two steps.
Expected
Result:
The voltage measured from Phase A and P hase C to
the neutr
al lead should be greater than 55% to 60%
of the voltage measured from Phase A to Phase B.
Results:
•
OK – The voltag e m e as ure d from Phase A and
Phase C to
the neutral lead is greater than 55%
to 60% of the voltage measured from Phase A to
Phase B. Proceed to Test Step 2.