Jeep KJ 2005 Service Manual page 253

8A - 2 AUDIO/VIDEO
AUDIO/VIDEO (Continued)
• Speakers
Certain functions and features of the audio system
rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munication Interface (PCI) bus network. The data
bus network allows the sharing of sensor informa-
tion. For diagnosis of these electronic modules or of
the data bus network, the use of a DRB III scan tool
and the proper Diagnostic Procedures manual are
recommended.
OPERATION
The audio system components are designed to pro-
vide audio entertainment and information through
the reception, tuning and amplification of locally
broadcast radio signals in both the Amplitude Modu-
lating (AM) and Frequency Modulating (FM) com-
mercial frequency ranges.
The audio system components operate on battery
current received through a fuse in the Junction Block
(JB) on a fused ignition switch output (run-acc) cir-
cuit so that the system will only operate when the
ignition switch is in the Run or Accessory positions.
On vehicles that are equipped with the optional
remote radio switches, the Body Control Module
(BCM) receives hard wired resistor multiplexed
inputs from the remote radio switches. The program-
ming in the BCM allows it to process those inputs
and send the proper messages to the radio receiver
CONDITION
NO AUDIO
NO RADIO DISPLAY
AUDIO SYSTEM DIAGNOSIS TABLE
POSSIBLE CAUSES
1. Fuse faulty.
2. Radio connector faulty.
3. Wiring faulty.
4. Radio ground faulty.
5. Radio faulty.
6. Speakers faulty.
7. Choke and relay faulty
1. Fuse faulty.
2. Radio connector faulty.
over the Programmable Communication Interface
(PCI) bus network to control the radio volume up or
down, station seek up or down, preset station
advance, and mode advance functions.
Refer to the owner's manual for more information
on the features, use and operation of each of the
available audio systems.
DIAGNOSIS AND TESTING - AUDIO
Any diagnosis of the Audio system should
begin with the use of scan tool. For information
on the use of the scan tool, refer to the appro-
priate Diagnostic information.
Refer to the appropriate wiring information.
WARNING: DISABLE
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
CORRECTION
1. Check radio fuse and Ignition-Off Draw (IOD)
fuse in Junction Block (JB). Replace fuses, if
required.
2. Check for loose or corroded radio connector.
Repair, if required.
3. Check for shorted or open wires. Repair wiring,
if required.
4. Check for continuity between radio chassis and
a known good ground. There should be
continuity. Repair ground, if required.
5. Refer to appropriate Diagnostic Service
Manual.
6. Replace speaker as necessary.
7. Replace choke and relay as necessary.
1. Check radio fuse and Ignition-Off Draw (IOD)
fuse in Junction Block (JB). Replace fuses, if
required.
2. Check for loose or corroded radio connector.
Repair, if required.
THE AIRBAG SYSTEM
KJ