TM-9-2320-272-23-1

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5

SEPTEMBER 2012

TM-9-2320-272-23-1 - Page 1282 of 1313

SYSTEM OVER-INFLATES TIRES - Continued

CAUTION

Turn battery switch to OFF position before disconnecting or connecting ECU wiring

harness. Failure to do so may result in damage to ECU.

b.

Turn battery switch to OFF position.

c.

Disconnect CTIS wiring harness cannon plug at ECU.

d.

Turn battery switch to ON position.

e.

Set multimeter to measure VDC.

f.

Connect multimeter red lead to CTIS wiring harness cannon plug pin V.

g.

Connect multimeter black lead to CTIS wiring harness cannon plug pin X.

h.

Meter reading should be between 18 and 26 VDC.

CONDITION/INDICATION

IS THERE BATTERY VOLTAGE PRESENT AT PINS X AND V ON CTIS WIRING HARNESS CANNON PLUG

AT ECU?

DECISION

YES - Go to Step (4).

NO - Perform Engine Fails To Crank troubleshooting (WP

0006).

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