CEL - FIRST CHART FOR DIAGNOSIS OF DDEC III/IV WHEN NO DDR IS AVAILABLE (Cont'd) -726280623

TM 9-2320-364-20-1

Section IV. TROUBLESHOOTING CHARTS (Cont.)

C. CEL - FIRST CHART FOR DIAGNOSIS OF DDEC III/IV WHEN NO DDR IS AVAILABLE (Cont'd)

STEP/SEQUENCE

RESULT

WHAT TO DO NEXT

CEL-7

Check ECM

Connectors

Disconnect the 5-way power

Terminals and

Replace ECM (para 7-57).

harness connector at the ECM.

connectors are okay.

Then go to CEL-30.

Check terminals at both the 5-way

power harness connector, and

Problem found.

Repair terminals/connectors

vehicle harness connector

(para 7-101). Then go to CEL-30.

(both the ECM and harness side)

for damage; bent, corroded and

unseated pins or sockets.

CEL-8

Intermittent Check

Note whether flashing "Check

Flashing a

Go to CEL-9.

Engine" light is reading a valid

valid code.

code or if it's just erratic.

Erratic or

Go to Chart 1, page 2-554.

intermittent "Check

Engine" light.

CEL-9

Check for Short

Plug DDR into DDL connector.

Select SWITCH/LIGHT STATS

on DDR.

Read Diagnostic Request SW.

ON.

Circuit #528 is shorted

status.

to ground. Repair short,

then go to CEL-30.

OFF.

Go to Chart 5, page 2-585.

CEL-30

Verify Repairs

Turn ignition off.

"Check Engine"

Repairs are complete.

Reconnect all connectors.

light comes on for up to

Turn ignition on.

5 seconds, then goes out.

Clear codes.

Turn ignition off.

"Check Engine"

All system diagnostics are

Turn ignition on while at the same

light is flashing.

complete. Please review this

time observing the "Check

section from the first step

Engine" light.

to find the error.

"Check Engine"

Go to START-1, page 2-539.

light comes on and

stays on.

2-553