CHART - 4 - NO "CHECK ENGINE" LIGHT DURING BULB CHECK OR CANNOT CLEAR CODES (Cont'd) -726280653

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- 6

Check for Open

Move black lead of voltmeter to

Less than

Ground line(s) (ckt #150 or 151)

socket D (of the 5-way power

10.0 volts on

has an open. Repair open.

harness connector).

any reading.

Then go to C 4-30.

Read voltage using red lead at

sockets A and C of the 5-way

power harness connector.

Greater than

Go to C 4--7.

Move black lead of voltmeter to

or equal to

socket E of the 5-way power

10.0 volts on

harness connector.

all readings.

Again read voltage at sockets A,

and C of the 5-way power

harness connector.

Move black lead to socket B

of 5-way. Check voltage at

A and C.

C 4- 7

Check ECM

Connectors

Check terminals at vehicle

Terminals

Replace ECM (para 7-57).

harness (especially B3 and B1)

and connectors

Then go to C 4-30.

and all the terminals in the 5-way

are okay.

power harness connectors (both

the ECM and harness side) for

Problem found.

Repair terminals/connectors

damage; bent, corroded and

(para 7-101).Then go to C 4-30.

unseated pins or sockets.

C 4-30

Verify Repairs

Turn ignition off.

"Check Engine"

Repairs are complete.

Reconnect all connectors.

light comes

Turn ignition on.

on for up to

Clear codes.

5 seconds,

Turn ignition off.

then goes out.

Turn ignition on while at the same

time observing the "Check

"Check Engine"

All system diagnostics are

Engine" light.

light does

complete. Please review this

not come on at all.

section from the first step to

find the error.

"Check Engine" light

Go to START-1, pg 2-539.

comes on and stays on.

*NOTE: Historical codes will not clear and engine hours/fuel consumption values will not update if main ECM power

(ckt #240 and #241) is switched off with ignition.

2-583