Fault Code Guide

Electrical Pre-Test
Procedure Result Action
Check for resistance between pin 2
(ground) of the X3 connector and the
battery ground terminal.
Resistance is greater than 0.3 ohms. Repair or replace the wiring as
needed. See Section 54.06, Subject
100.
Resistance is 0.3 ohms or less. Go to the next row in the table.
Remove the X1 (vehicle 21-pin) connector
from the transmission control unit (TCU).
Check the battery power circuit.
07/16/2004 f544483b
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
X1
Check for voltage from pins 12 and 15
(battery power circuit 232D) of the X1
connector to the battery ground terminal.
Voltage drops more than 0.2 volts
from the voltage measured at the
battery.
Repair or replace the wiring as
needed. See Section 54.06, Subject
100.
Voltage is within 0.2 volts of the
voltage measured at the battery.
Go to the next row in the table.
Turn on the ignition switch. Check the
ignition power circuit.
07/16/2004 f544483c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
X1
Check for voltage from pin 9 (ignition power
circuit 232E) of the X1 connector to the
battery ground terminal.
Voltage drops more than 0.2 volts
from the voltage measured at the
battery.
Repair or replace the wiring as
needed. See Section 54.06, Subject
100.
Voltage is within 0.2 volts of the
voltage measured at the battery.
Go to the next row in the table.
Freightliner AMT
3
and Mercedes-Benz Automated-Manual
Transmissions
26.03
Troubleshooting Without Fault Codes
Business Class M2 Workshop Manual, Supplement 20, September 2011301/2