1. Radio Cable in the A-Pillar
2. Cable Routed in the Dash
3. CB Radio Dash-Mounting Bracket
Fig. 10, Cable Routing, CB Radio

2
01/23/2013

f545993

1. AM/FM Radio
2. Cable Routed in the Dash
3. Radio Cable in the A-Pillar
Fig. 11, Cable Routing, AM/FM Radio

Page 18

Freightliner Service Bulletin, October 2015

Radio and Integrated Thin-Film Antenna Troubleshooting,
and Field Service Updates
> FLA COE
> FLB COE
> FLD Conventional
> Business Class
> FLC 112 Conventional

> Century Class Conventional
> Argosy COE
> Cargo
> Columbia

54-148
Freightliner
Service Bulletin

> Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

Stereo System Power Diagnostics
Step

1

Test Procedure
Turn the keyswitch to the
accessory position and press the
power button to turn the radio on.
Does the radio display remain on?

2

Measure the voltage at the radio
16 pin connector A. With the
keyswitch in the accessory position
measure for battery voltage at pins
4 (ignition) and 7 (battery) with the
negative lead at pin 8 (ground).
Is battery voltage present on both
pins 4 and 7?

Stereo System Power Diagnostics
Test Result
Action
The power supply is working properly. Continue
Yes
troubleshooting with the other diagnostic tables.
If the display immediately turns off or does not come on at
No
all, there is a problem with the power (+ or –) supply to the
radio. Go to step 2.
Both
Replace the radio.
Measure again with a known good ground. If voltage is now
present, use vehicle schematics to locate and repair a fault
Neither
with the ground circuit. Otherwise, follow the instructions
below for pins 4 or 7 fault action.
Check the appropriate fuse or circuit breaker and use
Only pin 4 or pin
vehicle schematics to locate and repair a fault with the
7
wiring from the power distribution device to the radio.

Table 10, Stereo System Power Diagnostics

1
A

F

B

E

C

D
A
2

C

D

B

E

A

F

9 11 13 15
10 12 14 16
3
1

3

5

7

2

4

6

8

09/06/2001

f543855

NOTE: See Table 11 for stereo jumper harness connectors pinout information.
A. To the radio.
1. Connector B (viewed from the terminal end)
3. Connector A (viewed from the wire insertion end)
2. Connector C (viewed from the terminal end)
Fig. 12, Stereo Jumper Harness

Connector B, 6-Pin
—
—
—

Stereo Jumper Harness Connectors
Connector C, 6-Pin
Connector A, 16-Pin
Wire Color
—
1
—
—
2
—
—
3
—

Freightliner Service Bulletin, October 2015

Circuit Description
—
—
—

Page 19

54-148

Radio and Integrated Thin-Film Antenna Troubleshooting,
and Field Service Updates

Freightliner
Service Bulletin

Connector B, 6-Pin
D
—
D
A
—
—
—
C
E
B
F
—
—

> FLA COE
> FLB COE
> FLD Conventional
> Business Class
> FLC 112 Conventional

> Century Class Conventional
> Argosy COE
> Cargo
> Columbia

Stereo Jumper Harness Connectors
Connector C, 6-Pin
Connector A, 16-Pin
Wire Color
—
4
Red
—
5
—
—
6
Orange/White
—
7
Yellow
A
8
Black
C
9
Violet
D
10
Violet/Black
—
11
Dark Gray
—
12
Gray/Black
—
13
White
—
14
White/Black
B
15
Dark Green
E
16
Green/Black

> Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

Circuit Description
Ignition
—
Dimmer
Battery
Ground
Right Rear (+)
Right Rear (-)
Right Front (+)
Right Front (-)
Left Front (+)
Left Front (-)
Left Rear (+)
Left Rear (-)

Table 11, Stereo Jumper Harness Connectors

Tape Deck Diagnostics
Step
1

Test Procedure
Visually inspect inside the tape
deck.
Are foreign objects visible?

2

3

Tape Deck Diagnostics
Test Result
Action
The objects need to be removed. The tape deck may need
Yes
cleaning when cleared. These operations are not covered
under warranty.
No
Go to step 2.

Insert a known good tape that is no
longer than 45 minutes per side.

Yes

The customers tape is faulty. No further action is necessary.

Does the tape play correctly?
Insert a cleaning cassette to clean
the tape head and drive
mechanisms. Retest with a known
good tape after cleaning is
complete.

No

Go to step 3.

Yes

Replace the radio/tape deck.

No

The cassette deck needed cleaning. No further repair is
necessary.

Is the problem still present?
Table 12, Tape Deck Diagnostics

Page 20

Freightliner Service Bulletin, October 2015

Radio and Integrated Thin-Film Antenna Troubleshooting,
and Field Service Updates
> FLA COE
> FLB COE
> FLD Conventional
> Business Class
> FLC 112 Conventional

> Century Class Conventional
> Argosy COE
> Cargo
> Columbia

> Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

54-148
Freightliner
Service Bulletin

Speaker Diagnostics
Step

1

Test Procedure
After finishing the speaker test,
reset the balance, fader, treble and
bass controls to their settings at
the start of the test or to the center
(zero) position.
Which speakers are not
functioning?

2

3

4

5

Verify operation of the subwoofers.
Turn on the radio and verify
operation of the subwoofers.
Which subwoofer is not working?
Check amplifier voltage. Check
between pin A12 of the amplifier
harness and cab ground for battery
power. See Fig. 13, Fig. 14, and
Fig. 15. The voltage should be
within 0.5 volts of battery voltage.
Is the voltage correct?
Verify operation of the speakers.
Turn on the radio and verify
operation of the speakers.
Are the rear speakers working?
Check the resistance. Check the
subwoofer speaker resistance. A
good speaker should have a
resistance value of 2 to 10 ohms.
Measure the resistance across the
speaker input terminals.

Speaker Diagnostics
Test Result
Action
Check for a speaker lead shorted to ground. This causes all
audio to stop functioning. If one of the speaker leads is
shorted to ground for an extended period, the radio audio
All Speakers
will go in to shutdown mode. If a short is found and
corrected, and there is still no audio, give the radio ample
time to cool (come out of shutdown mode). If there is still
no audio, replace the radio.
Subwoofer(s)
Go to step 2.
Front Speakers Go to step 11.
Rear Speakers Go to step 14.
Both

Go to step 3.

Left or Right
Only

Go to step 6.

Yes

Go to step 4.

No

Check the circuit breaker and the amplifier power leads.
Repair or replace as required.

Yes

Go to step 5.

No

Check the speaker leads. If they are OK, replace the radio.

Yes

Go to step 8.

No

Replace the speaker.

Is the resistance OK?

Freightliner Service Bulletin, October 2015

Page 21

54-148

Radio and Integrated Thin-Film Antenna Troubleshooting,
and Field Service Updates

Freightliner
Service Bulletin

Step

6

7

8

> FLA COE
> FLB COE
> FLD Conventional
> Business Class
> FLC 112 Conventional

Test Procedure
Check amplifier output. Tune the
radio to a frequency with no active
radio station, then set the volume
to a comfortable level. Remove the
pins from the connector for the
subwoofer speaker that is not
functioning (pins B11 and B12 for
the right subwoofer, pins B9 and
B10 for the left subwoofer). See
Fig. 13 and Fig. 14. With the
connector attached to the amplifier,
check the AC voltage between the
disconnected pins and a known
good ground. Be sure the balance
and fader controls are set to the
center (0) position.
Are all output readings the same?
Check for AC voltage output from
the amplifier. Tune the radio to a
frequency with no active radio
station, then set the volume to a
comfortable level. Remove the pins
from the connector for the
subwoofer speaker that is not
functioning (pins B11 and B12 for
the right subwoofer, pins B9 and
B10 for the left subwoofer). See
Fig. 13 and Fig. 14. With the
connector attached to the amplifier,
check the AC voltage between the
disconnected pins and a known
good ground. Be sure the balance
and fader controls are set to the
center (0) position.
Is AC voltage present?
Verify operation of the rear
speakers. Turn on the radio and
verify the operation of the rear
speakers.
Are the rear speakers working?

Page 22

> Century Class Conventional
> Argosy COE
> Cargo
> Columbia

Speaker Diagnostics
Test Result

> Coronado
> Business Class M2
> Cascadia
> 108SD/114SD

Action

Yes

Check the speaker leads and repair or replace as
necessary.