Section
4
TROUBLESHOOTING
D. CHART
19 -POWER
CONTROL
INPUT
INOPERATIVE
NOTE — This chart IS onlyto be used If
1) All basic mechanical
checks and physical 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.
C19-1
Identify
Power
Control
Application
l Determine
how
Power Control
input (ckt#524)
is being used.
l Plug DDR into 12-pin DDL
connector and select MODE 03
(PROM ID).
C19-2
Test Throttle
Inhibit
Feature
l Start and run engine.
l Plug DDR into the 12 pin DDL
connector and select Mode 29
(MISC SWITCHES) for display.
l Place vehicle in condition where
throttle inhibit is supposed
to
occur and observe DDR display
line labeled “POWER CTL SW”
(on coaches, this occurs when a
passenger door is open).
C19-3
Check
ECM
Connectors
l Turn ignition off (if still on).
l Disconnect
the vehicle harness
connector at the ECM (if not
already disconnected).
l Check terminals at the vehicle
harness connector (both the ECM
and harness side) for damage;
bent, corroded,
and unseated
pins or sockets.
TM 9-2320-363-20-1
RESULT
WHAT TO DO NEXT
Used for
Go
to C19-2.
throttle inhibit
Used for
Go
to C19-4.
engine protection
(PC SHUT DOWN).
DDR display
Feature
appears to be operational
reads “ON’”.
at the moment. Problem maybe
intermittent. Refer to Cl -2, page
3-136, for help on resolving
intermittent faults.
DDR display
An open exists in either the
reads “OFF”.
Power Control line (ckt #524) or
the switch (or relay) in series
with it. Contact Direct Support.
(If an open is not found, go to
C19-5).
Terminals and
Replace
ECM, page 4-192.
connectors are okay.
Then go to C19-30.
Problem found.
Repair
terminals/connectors,
Connectors are okay.
page 3-2. Then go to C19-30.
3-197
