9
−
9
62-11389
NO
YES
YES
YES
NO
NO
YES
NO
YES
NO
YES
YES
.
YES
NO
YES
NO
YES
NO
NO
YES
NO
NO
NOTE : Ensure the run relay is ener-
gized during test . With ENSSN un-
plugged during testing , unit will stall
& go through start sequence again .
Unit will not start . This is normal .
Verify there is at least 11 VDC going
into the ENSSN 12V terminal ?
START HERE
Start unit.
Using strobe light 07-00177-01
or equivalent, check engine
RPM. Is RPM equal to or over
2,530?
Check for high resist-
ance or an open in the
ENSSN ground circuit.
Did you find and correct
the condition?
Check high speed mechanical stop
on injection pump assembly for
loose screws or tampering.
Are the screws loose?
Check for high resist-
ance or an open
between ENSCU ter-
minal 25 & ENSSN
12V terminal. Did you
find and correct the
condition?
System
OK
System
OK
System
OK
System
OK
System
OK
System
OK
Set proper high speed RPM
(Table 2-1). Lock screws in
place and rewire.
Did you find and correct the
condition?
Using jumper wire, check for 5
VDC at ENSCU terminal 10.
Do you have 5 VDC at terminal
10?
Remove new ENSCU
and re-install old
ENSCU back into unit,
ENSCU is not the fault.
Review results of above
tests with your super-
visor. If necessary, go to
the beginning of the tree
& test again.
Check for proper internal mechanical
operation of injection pump assembly
and governor assembly. Did you find
and correct the condition?
Replace ENSCU. Did you
find and correct the condition?
Review results of
above tests with your
supervisor. If neces-
sary, go to the begin-
ning of the tree & test
again.
Check for open or high resist-
ance on circuit between
ENSSN and ENSCU. Did you
find and correct the condition?
Replace ENSSN. Did you find
and correct the condition?
Remove new ENSSN and re-in-
stall old ENSSN back into unit,
ENSSN is not the fault.
Review results of above tests
with your supervisor. If neces-
sary, go to the beginning of the
tree & test again.
Figure 9
−
1 ENSCU Diagnostic Tree - 1 Long, 1 Short LED Code
