CHART - 4 - NO "CHECK ENGINE" LIGHT DURING BULB CHECK OR CANNOT CLEAR CODES (Cont'd) -726280651

TM 9-2320-364-20-1

Section IV. TROUBLESHOOTING CHARTS (Cont.)

D. CHART - 4 - NO "CHECK ENGINE" LIGHT DURING BULB CHECK OR CANNOT CLEAR CODES (Cont'd)

STEP/SEQUENCE

RESULT

WHAT TO DO NEXT

C 4- 4

Check for Open

Remove jumper wire. With ignition

Less than

The ignition line (ckt #439) is

on, read voltage on vehicle

10.0 volts.

open. Repair open. Then go

harness connector, socket B3

to C 4-30.

(red lead) to a good ground

(black lead).

Greater than

Go to C 4--5.

or equal to 10.0 volts.

C 4- 5

Check for Bat +

Turn ignition off.

Less than

Either one of the 20 Amp, DDEC

Disconnect the 5-way

10.0 volts on

circuit breakers (CB22 or CB23)

power harness connector.

any reading.

is blown and/or the Battery

Read voltage at the 5-way power

Power line(s) (ckt #240 or #241)

harness connector. Socket A (red

has an open or short to

lead) to a good ground (black

ground. Check that the battery

lead).

power (ckt #240 and #241)

Repeat voltage readings on 5-way

are not switched off when

power harness connector, keeping

the ignition is turned off (see

the black lead to a good ground

note below). Repair problem.

and the red lead to socket C.

Then go to C 4-30.

Greater than

Go to C 4--6.

or equal to

10.0 volts on

readings.

*NOTE: Engine update information may not update if main ECM power (ckt #240 and #241) is switched off

with/or before ignition.

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