Go to 31-7
Go 31-5
Go to 31-3
Section 4
TROUBLESHOOTING
CHARTS
TM 9-2320-63-20-1
E. CODE 31 l FAULT ON AUXILIARY OUTPUT
NOTE
— Thischartisonlytobeusedif:
1) Allbasicmechanicalchecksandphysicalinspectionshavebeenperformedwithnoproblemfound,and
2) DiagnosisofDDEC-II
wasstartedatstepStart-
1(pag e3-121)andyouhavenowbeenreferredhere.
31-1
Verify Bulb Operation
(*See Note Below)
l Turn ignition off.
l Turn ignition on (engine not
running).
l Note status of the following lights:
—“Check Engine” (CEL)
Go to31-2
31.2
Bulb Check
l Turn ignition off.
l Check whether bulb(s) IS (are)
burned out or otherwisedamaged
31-3
Check for Open
l Disconnect
the vehicle harness
connector at the ECM.
l Turn ignition on.
l Read voltageonthevehicleharness
connector, keeping the black lead
on a good battery ground and
probing the following sockets with
the red lead:
—B1 (CEL)
—B2 (SEL)
RESULT
WHAT TO DO NEXT
All lights go
on for 5 seconds and then
go out.
At least one
of the lights never turn on.
All lights go
on for 5 seconds and at
least one light stays on.
Bulb(s)is okay.
Bulb(s) is not okay.
Replace bulb(s), page 4-193.
I
Then go to 31-30.
Greater than
Goto
31-4.
10 volts on all readings.
Less than
Open exists in wire where less
10 volts on any reading.
than 10 volts was read.
Contact Direct Support.
3-239
