D. CHART 18-ENGINE
BRAKE
NOTE — This chart IS only to be used if:
Section
4
TROUBLESHOOTING
CHARTS
INOPERATIVE
TM 9-2320-363-20-1
1) All base mechanical
checks
and phtsical
inspections have been performed with no problem found
and
2) Diagnosis of DDEC-II was started at step Start-1 (page 3-121) and you have now been referred here.
STEP/SEQUENCE
RESULT
WHAT TO DO NEXT
C18-1
Verify
Control
Logic
l Start engine
and
run
at idle
(no
Display
read
“’OFF”.
Feature
is programmed
for
throttle applied).
engine brake control. Go to
C18-2.
. Plug in DDR and select MISC
OUTPUTS (Mode 30).
l observe
DDR display on line
labeled ENG BRK ENBLE
C18-2
Verify
Engine
Brake
Enable
Operation
l Rev Up the engine then quickly
take
your foot off the throttle while
observing
the DDR display line
labeled ENG BRK ENBLE.
DDR is always
Replace ECM, page 4-192.
reading “OFF”.
Then go to C18-30.
DDR reads “OFF”
The
ECM is operating properly.
at first. then reads
Check for open in engine brake
"ON" when foot is
enable line (ckt#508).
Then go
let off throttle.
to C18-4.
As the engine
returns to idle,
this display reads
“’OFF’” once again.
3-193
