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 1234 of 1313

FIELD MAINTENANCE

SYSTEM REPEATEDLY RESUMES CYCLING 30 SECONDS AFTER MODE LIGHT STOPS FLASHING

INITIAL SETUP:

Tools and Special Tools

Tool Kit, General Mechanic's: Automotive

(Volume 5, WP

0826, Table 1, Item 56)

Soap Solution

Test Set, Electronic Systems

(Volume 5, WP

0826, Table 1, Item 51)

Personnel Required

(2)

References

Point to Point Schematics

References (cont.)

TM 9-2320-272-10

Volume 3, WP

0490

Volume 3, WP

0491

Equipment Condition

Vehicle parked and engine shut down.

(TM

9-2320-272-10)

TROUBLESHOOTING PROCEDURE

SYSTEM REPEATEDLY RESUMES CYCLING 30 SECONDS AFTER MODE LIGHT STOPS FLASHING

NOTE

•

Conduct these malfunction tests if the system repeatedly resumes cycling 30 seconds

after mode light stops flashing. This procedure will check for leaking air lines between

wheel valves and wheels. It will also check for a faulty wheel valve.

•

The ECU is programmed to check tire pressures 30 seconds after completing a pressure

changing sequence. The ECU does this to verify that all wheel valves are properly closed

before making pressure checks at fifteen minute intervals. If the ECU repeatedly checks

pressure 30 seconds after a mode light stops flashing, it is indicative of one or more tires

losing air.

TM 9-2320-272-23-1

0147

0147-1