TM-9-2320-272-23-2
TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)
TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 2 OF 5
SEPTEMBER 2012
TM-9-2320-272-23-2 - Page 58 of 1417
INTRODUCTION - Continued
T0832DAA
SENSOR 2A HI
SENSOR 2B LOW
NOT USED
NOT USED
NOT USED
BLUE (LEFT) SOLENOID COMMON
YELLOW (RIGHT) SOLENOID HOLD
YELLOW (RIGHT) SOLENOID COMMON
NOT USED
NOT USED
LAMP -
B- GROUND
NOT USED
DDU B-
DIAGNOSTIC OUTPUT
DDU B+
20
21
11
10
1
2
12
13
22
23
14
4
3
5
15
24
25
16
6
7
17
26
27
18
8
9
19
28
DIAGNOSTIC INPUT
LAMP +
YELLOW (RIGHT) SOLENOID PUMP
BLUE (LEFT) SOLENOID HOLD
BLUE (LEFT) SOLENOID DUMP
SENSOR 2B HI
SENSOR 2A LOW
B+ PERM
NOT USED
NOT USED
NOT USED
IGNITION SWITCHED B+
Figure 1.
ABS Wiring Harness ECU Connector.
f.
Codes 72, 73, 78, and 79 indicate that a solenoid or its cable has a short to ground. The most likely
cause is a damaged cable or solenoid. To check this, remove ABS main wiring harness connector
from ECU and check for continuity between pins 3, 13, and 23 for (BLUE) forward valve cable and
4, 14, and 24 for (YELLOW) rear valve cable and vehicle B+, with battery and starter switches in
the ON or RUN position. If resistance is less than 10 MÙ in any test, move battery and starter
switches to the OFF position. Repair or replace ABS main wiring harness connector or defective
ECU.
g.
Code 91 indicates that ABS voltage is below 8 volts. The most likely causes include, damaged, or
corroded lead terminals, blown 3 amp fuse, or a splice in the ABS power supply circuit. Check
ground, 3 AMP fuse connections, and ABS power supply connections. If power is coming from
somewhere other than the vehicle electrical system, make sure the test battery is fully charged or
the voltage converter has adequate voltage (21.0 to 33.0 volts) and current capacity (11 amp). DO
NOT USE A BATTERY CHARGER.
h.
Code 92 indicates that the ABS power supply voltage is above 33.1 volts. The most suspect cause
is a malfunctioning voltage regulator. Repair or replace as necessary.
i.
Code 80, 93, E0-E9, or EA-EF indicates that the ECU is likely defective. Replace ECU and recheck.
j.
Code 13, 14, 23, 24, 42, and 43 will not be set or erased from memory until the vehicle is driven
above 6 mph.
k.
A CA code is an invitation to clear all faults stored in history.
l.
A CC code will be displayed during the third consecutive time that a clear all is attempted. This is
an invitation to clear configuration and should be avoided. If a CC is displayed, power down the
system and then power up the system.
8.
This chapter cannot list all malfunctions that may occur. If a malfunction occurs that is not listed in the table,
notify supervisor.
9.
If malfunction corrective action does not correct malfunction, notify supervisor.
TM 9-2320-272-23-2
0154
0154-3
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