Section 4
TM 9-2320-363-20-1
TROUBLESHOOTING CHARTS
C. CEL l FIRST CHART FOR DIAGNOSIS OF DDEC-II WHEN NO DDR IS AVAILABLE (Cont’d.)
CEL-4
Verify Code(s)
l Remove jumper wire between pins
A and M.
l Turn ignition on.
l Obtain a DDR.
l Clear codes.
l Turn ignition off, then back on.
l Note status of “Check Engine”
light.
CEL-5
Verify Code(s)
with the Engine
Running
l Attempt to start and run the engine.
l Try to get the "Check Engine” light
on by:
—warming up the engine
—slowly changing the engine
from idle to no load speed.
l Run engine until the "Check Engine”
light comes on or for I minute.
CEL-6
Check for Open
l Turn ignition off.
l Disconnect the vehicle harness
connector at the ECM.
l Install a jumper wire between
sockets C1 and El of the vehicle
harness connector.
l Read resistance between pins K
and M of the 12 pin, DDL
connector.
l Also read resistance between pin
A of the DDL connector and a
good ground.
WHAT TO DO NEXT
Read codes (by installing
jumper wire again) and follow
appropriate diagnostic chart.
(See Index on page 3-101).
Go to CEL-5.
Go to CEL-8.
Go to Chart 2, page 3-141.
Previous codes should be
regarded as intermittent. Go to
Chart 1, page 3-136.
Read codes (by installing
jumper wire again) and follow
appropriate diagnostic chart.
(See Index on page 3-101).
Go to CEL-7.
An open exists either in the
Diagnostic Request line (ckt
#451 ) or in the DDL ground line
(ckt #901). Repair open. Then
go to CEL-30.
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