CHART - 6 - "CHECK GAUGES" LIGHT ON AND NO ACTIVE CODE ON DDR

TM 9-2320-364-20-1

2-14. DDEC III/IV TROUBLESHOOTING (CONT).

Section IV. TROUBLESHOOTING CHARTS (Cont.)

D. CHART - 6 - "CHECK GAUGES" LIGHT ON AND NO ACTIVE CODE ON DDR

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/IV was started at step START-1, pg 2-539, and you have now been referred here.

This is a Digital output function.

STEP/SEQUENCE

RESULT

WHAT TO DO NEXT

C 6-1

Determine "Check

Gauges" Light Status

Turn ignition on (engine not

"Check Gauges"

This is the normal operation.

running) while at the same time

light comes on for

Unless other problems exist,

observing "Check Gauges" light.

up to 5 seconds,

return to service.

then goes out.

"Check Gauges" light

Go to C 6-2.

comes on and stays on.

C 6-2

Light Status - DDR

Plug in DDR.

Select SWITCH/LIGHT STATS.

CGL reads on.

Go to C 6-4.

Read CGL.

CGL reads off.

Go to C 6-3.

C 6-3

Check for Short

Turn ignition off.

"Check Gauges"

"Check Gauges" light driver line

Disconnect the vehicle harness

light comes on

(ckt #509) is shorted to ground.

connector at ECM.

and stays on.

Repair short. Then go to C 6-30.

Turn ignition on (engine not

running) while at same time

observing "Check Gauges" light.

"Check Gauges"

Go to C 6-4.

light stays off.

C 6-4

Check ECM

Connectors

Check terminals at vehicle

Terminals

Replace ECM (para 7-57).

harness connector (both ECM

and connectors

Then go to C 6-30.

and harness side) for damage

are okay.

bent, corroded, and unseated

pins or sockets. Pay close

Problem found.

Repair terminals/connectors

attention to B2 and B3.

(para 7-101). Then go to C 6-30.

2-589