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 115 of 1417
ABS - CODE S2A 03 (LEFT SIDE - BLUE CHANNEL) - Continued
STEP
3.
IS LEFT REAR-REAR WHEEL SPEED SENSOR CIRCUIT WIRING SHORTED TO ANOTHER CIRCUIT?
a.
Ensure battery and start switches are in the OFF position.
T0947DAA
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 3.
ABS Wiring Harness 28-pin ECU Connector.
b.
Disconnect main 28-pin connector at ECU (Volume 3, WP
0452).
c.
Connect multimeter red lead to 28-pin connector, terminal 1. Refer to point to point schematics.
d.
Connect mutimeter black lead to the remaining 28-pin connector terminals, except terminal 10.
e.
Meter readings should be greater than 10,000 ohms for each measurement. Note readings.
f.
Connect multimeter black lead to 28-pin connector, terminal 10.
g.
Connect mutimeter black lead to the remaining 28-pin connector terminals, except terminal 1.
h.
Meter readings should be greater than 10,000 ohms for each measurement. Note readings.
CONDITION/INDICATION
IS LEFT REAR-REAR WHEEL SPEED SENSOR CIRCUIT WIRING SHORTED TO ANOTHER CIRCUIT?
DECISION
YES - Replace ABS wiring harness (Volume 3, WP
0467). Go to Step (4) to verify problem is solved.
NO - Replace ABS ECU (Volume 3, WP
0452). Go to Step (4) to verify problem is solved.
TM 9-2320-272-23-2
0162
0162-6
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