STEP/SEQUENCE
RESULT
WHAT TO DO NEXT
TM 9-2320-363-20-1
Section 4
TROUBLESHOOTING CHARTS
D.
CHART 21 - AUXILIARY ENGINE PROTECTION #1 OR #2 INOPERATIVE
NOTE - This chart is only to be used if:
1) All basic mechanical checks and physical inspections have been performed with no problem found,
and
2) Diagnosis of DDEC-III was started at step Start-1, pg 3-345.41 and you have now been referred here.
C 21-1
Check Input/Output
Configuration
Turn ignition on.
Plug in DDR.
Not configured for
Reconfigure ECM for proper
Select ECM input/output
auxiliary #1 or #2
input(s).
configuration.
protection.
Write/print pin assignments for
Auxiliary #1 or #2 protection.
Data obtained
Go to C 21-2.
C 21-2
Determine OEM
Supplied Switch
This input function is designed to operate when an OEM supplied switch or relay supplies battery
ground to this (these) wire(s).
Determine OEM supplied device then go to C 21-3.
C 21-3
Attempt to Force
"On"
Plug in DDR.
Switch read on.
Switch or relay is bad.
Select switch light status
Replace, then go to C 21-30.
Install a jumper wire from OEM
wire, to battery ground.
Switch read off.
An open exists in the wire
Observe switch status.
repair open then go to C 21-
30.
C 21-30
Verify Repairs
Turn Ignition on.
Switch read on, and
Repairs complete clear
Select switch/light status
logs code.
return to service.
Jumper wire to ground, or force
switch/relay to ground wire.
Switch reads off, and
Repairs are complete. Go
no codes.
back to Step 1 to find the
error.
Change 3 3-345.161
