Section 4
TM 9-2320-363-20-1
TROUBLESHOOTING CHARTS
D. CHART 4- NO “CHECK ENGINE” LIGHT DURING BULB CHECK OR CANNOT CLEAR CODES (Cont’d
C4-6 Check for Ground
l Move black lead of voltmeter to
socket C (of the 6-way power
connector).
l Read voltage using red lead at
sockets A, B. E and F of the 6-way
power harness connector.
l Move black lead of voltmeter to
socket D of the 6-way power
harness connector.
l Again read voltage at sockets A,
B, E and F of the 6-way power
harness connector.
C4-7 Check ECM
Connectors
l Check terminals at the vehicle
harness (especially B3 and B1 )
and all the terminals in the 6-way
power harness connectors (both
the ECM and harness side) for
damage; bent. corroded and
unseated pins or sockets.
C4-30 Verify Repairs
l Turn ignition off.
l Reconnect all Connectors.
l Turn ignition on.
. Clear codes
l Turn ignition off.
l Turn ignition on while at the same
time observing the “Check
Engine” light.
WHAT TO DO NEXT
Ground line(s) (Ckt #l 50) has an
open. Repair open, page 3-2.
Then got to C4-30.
GO to C4-7.
Replace ECM, page 4-192.
Then go to C4-30.
Repair terminais/connectors,
page 3-2. Then go to C4-30.
Repairs are complete.
All system diagnostics are
complete. Please review this
section from the first step to
find the error.
Go to START-1, page 3-121.
NOTE: Historical codes will not clear and engine hours/fuel consumption values will not update if main ECM power (circuits
#240 and #241 ) IS switched off with-ignition.
3-167
