Section 4
TROUBLESHOOTING CHARTS
D. CHART 7. NO DATA LINK AND BULB CHECK OKAY (Co nt’d.)
TM 9-2320-363-20-1
C7-4 Check for Open
l Turn off ignition.
l Remove all jumpers from 12-pin
DDL connector.
l Place jumper across pins J and K
on the 12-pin DDL connector.
l Unplug the vehicle harness
connector and measure resistance
between sockets Cl and C2.
G o t o C 7 - 5 .
C7-5 Check for Short
l Remove jumper wires from the
12-pin DDL connector.
l Read resistance between sockets
C1 & C2 of the vehicle harness
connector.
C7-6 Check for Short to Ing.
& Ground
l Remove all jumpers from the 12-
pin DDL connector.
l Measure resistance between
sockets J and A. then J and H
next. Measure resistance between
sockets K and A, then K and H
of the DDL connector.
C7-7 Check DDR on Another
Engine
l Connect DDR to another engine
and read PROM ID or any other
parameter in the menu.
RESULT
I
WHAT TO DO NEXT
One or both data lines (ckt #900
or #901) is open. Contact Direct
support.
The two data lines are shorted
together (ckt #900 and #901).
Contact Direct Support.
Go to C7-6.
A short exists between a data
line and ignition (ckt #439) or
ground (ckt #150). Contact
Direct Support.
Go to C7-7.
Go to C7-30
The DDR is probably defective.
See DDR instruction manual for
repair.
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