Grand Cherokee 4WD Laredo V8-4.7L (2002)
Speaker: All Technical Service Bulletins
Audio System - Buzz Sound in Cold Temperatures
NUMBER: 08-025-03
GROUP: Electrical
DATE: Aug. 15, 2003
SUBJECT:
Short Buzz-Like Sound When Radio Is First Turned On In Cold Temperatures
OVERVIEW:
This bulletin involves the diagnosis and possible replacement of a front door speaker/amplifier.
MODELS:
2002 - 2003
(KJ)
Liberty (Domestic Market)
2002 - 2003
(KJ)
Cherokee (International Market)
NOTE:
This bulletin applies to vehicles build prior to March 24, 2003 (MDH 0324XX) and equipped with a Premium Infinity radio system (sales code
RCJ).
SYMPTOM/CONDITION:
A customer may experience a momentary buzz-like sound from a rear speaker when the vehicle radio is first turned on. In ambient temperatures of 0° C
(32° F) or less, the duration of the buzz-like sound may be as long as one second. The condition is temperature sensitive and will not occur in warm
ambient temperatures. The customer may notice that the buzz-like sound from the rear speaker only occurs on one side of the vehicle (drivers side or
passenger side).
The buzz-like sound may be caused by an internal amplifier fault in one of the front door radio speakers. Because the front door speaker also drives the
rear speaker, on its respective side of the vehicle, the buzz-like sound in the rear speaker may actually be caused by an amplifier fault in the respective
front door speaker.
DIAGNOSIS:
1.
The vehicle radio speakers must be cold to diagnose this condition. Ideally, 5° C (41° F) or less.
2.
Turn the radio on and set volume to medium level.
3.
Without starting the vehicle, perform ten (10) complete cycles by switching the ignition switch between the OFF position and the ON position.
Remain in each ignition switch position for only one (1) second before moving back to the other ignition switch position.
4.
Determine if the condition is present and from which rear speaker(s) the buzz-like sound occurs.
5.
If the buzz-like sound occurs in one or both of the rear speakers, and the customer has described the condition, then perform the Repair Procedure.
PARTS REQUIRED:
REPAIR PROCEDURE:
1.
Disconnect and isolate the battery negative cable.
2.
Remove the front door trim panel.
3.
Remove the speaker mounting screws.
4.
Remove the speaker from the door and disconnect the wire harness connector.
