Century Estate Wagon L4-151 2.5L VIN R TBI (1987)
Radio/Stereo: All Technical Service Bulletins
Radio - Inoperative Due to Logic Lock Up
Bulletin:
87-9-4
Date:
Sept., '87
Ref. No. 87-174-9
Corp. Ref. No. 739002
SUBJECT:
RADIO INOPERATIVE DUE TO LOGIC LOCK UP
MODELS AFFECTED: ALL 1987 ELECTRA/PARK AVENUE, LESABRE, REGAL, CENTURY, SOMERSET, SKYLARK AND SKYHAWK
MODELS WITH 2000 SERIES RADIOS AND THREE BUTTON CASSETTES, OPTION UM6
2000 SERIES RADIO WITH 3 BUTTON CASSETTE
Some 1987 vehicles with 2000 series radios and three button cassettes (Option codes UM6) may exhibit a condition in which the radio portion of the unit
is inoperative with the cassette deck operating normally. This is caused by an internal radio "logic lock-up" situation resulting from electrostatic
discharge (ESD) through the tape deck door.
To check for this condition, remove the vehicles' battery power by disconnecting and reconnecting the negative battery cable. If the radio returns to
normal operation after this is done, it should be sent to an AC Delco Service Center for the addition of circuit protection against future ESD damage. If
the radio is not sent to an AC Delco center for repair, the customer may experience the same condition again.
When submitting the radio to the repair center, describe the problem as "Radio Logic Lock-up". This description is necessary because the radio will
appear normal when tested out of the car.
Use applicable labor time.
