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 1286 of 1313

FIELD MAINTENANCE

SLOW AIR RECOVERY OR OCCASIONAL LOW AIR WARNING DURING BRAKING

INITIAL SETUP:

Tools and Special Tools

Tool Kit, General Mechanic's: Automotive

(Volume 5, WP

0826, Table 1, Item 56)

Multimeter

(Volume 5, WP

0826, Table 1, Item 34)

Test Set, Electronic Systems

(Volume 5, WP

0826, Table 1, Item 51)

Personnel Required

(2)

References

Point to Point Schematics

References (cont.)

Volume 2, WP

0322

Volume 2, WP

0324

Volume 5, WP

0813

Equipment Condition

Vehicle parked and engine shut down.

(TM

9-2320-272-10)

TROUBLESHOOTING PROCEDURE

SLOW AIR RECOVERY OR OCCASIONAL LOW AIR WARNING DURING BRAKING

NOTE

Conduct these malfunction tests if air recovery is slow, or there is an occasional low air

warning during braking. This procedure will check for the pressure switch lead not making

contact, and no continuity between pressure switch and CTIS wiring harness cannon plug at

the Electronic Control Unit (ECU). It will also check for a faulty CTIS wiring harness, pressure

switch, and ECU.

TM 9-2320-272-23-1

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