DDR TEST -726280555

TM 9-2320-364-20-1

Allow engine to cool before performing troubleshooting maintenance. If necessary use insulated pads

and gloves. Hot engine components will burn and cause injury to personnel.

Remove all jewelry such as rings, dog tags, bracelets, etc. If jewelry or tools contact positive electrical

circuits, a direct short may result. Damage to equipment, injury or death to personnel may occur.

NOTE

Battery voltage surges, while cranking the

engine, may blank out or reset DDR.

DDR TEST

(1) Remove two mounting screws and heat

shield from DDEC ECM.

(2) Disconnect power harness connector

MC17 from DDEC ECM with connector

removed.

(3) Turn ON ENGINE switch

(TM 9-2320-364-10).

(4) Select MODE 04 (ENGINE RPM)

(5) Turn engine switch to start and

observe DDR display.

(a) If engine RPM is more than 60,

turn OFF ENGINE switch and go

to Step 8 of this Fault.

(b) If engine RPM is less than 60, turn

OFF ENGINE switch and go to

Step 6 of this Fault.

DDEC ECM connector terminals are easily

damaged. Use care when connecting and

disconnecting connectors.

RESISTANCE TEST

(1) Loosen screw and disconnect engine

harness connector at DDEC ECM.

(2) Set multimeter select switch to ohms.

(3) Are there 100 to 200 ohms present

between wires 109 and 110 at engine

harness connector, terminals T1

and T2?

(a) If there are less than 100 ohms

or more than 200 ohms present,

connect engine harness

connector and go to A4 Code 41

Step 2.

(b) If there are 100 to 200 ohms

present, go to Step 7 of this Fault.