CHART - 10 - VARIABLE SPEED GOVERNOR (VSG OR CRANE HIGH IDLE) INOPERATIVE

TM 9-2320-364-20-1

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

Section IV. TROUBLESHOOTING CHARTS (Cont.)

D. CHART - 10 - VARIABLE SPEED GOVERNOR (VSG OR CRANE HIGH IDLE) INOPERATIVE

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.

STEP/SEQUENCE

RESULT

WHAT TO DO NEXT

C 10-1 through C 10-4 (Deleted)

C 10-5

Check Throttle

Position Sensor

Turn ignition on.

At 0% throttle.

Go to C 10-6.

Plug DDR into DDL

connector.

Greater than 0%

Check throttle position sensor

Engine at no throttle.

throttle.

adjustment. Go to 21-4

Read TPS PCT

(page 2-643).

using DDR.

C 10-6

Check if ECM is

Reading VSG Speed

Start engine (TM 9-2320-364-10).

DDR display

Go to C 10-7.

Position transmission range

changes smoothly from

selector to N (neutral).

idle (typically 650 RPM) to

Select the VSG RPM on the

high idle speed

DDR reader.

(1275 RPM).

Push ENGINE HIGH IDLE LATCH

switch to LATCH and release.

DDR does not

Go to C 10-9.

Shut off engine

change at all or does

(TM 9-2320-364-10).

not change smoothly.

C 10-7

Verify Complaint

Start engine (TM 9-2320-364-10)

RPM is increasing.

Problem no longer exists. Go to

and run at idle.

C 1-2 for more information (page

Using the DDR reader, make sure

2-555).

that TPS PCT is 0.

Position ENGINE HIGH IDLE

RPM does not increase.

Go to C 10-8.

LATCH switch to LATCH and

release.

2-609