SERVICE MANUAL UPDATE-SEC. 8A RADIO/AUDIO SYSTEM CHART REV.

SUBJECT: SECTION 8A - RADIO/AUDIO SYSTEM (ETR) CHART REVISION

VEHICLES AFFECTED: 1993 "N" MODELS

REFERENCE:

--------- 1993 Oldsmobile "N" Car Service Manual

In SECTION 8A, Cell 150 Page 4 has diagnostic information that may cause some technicians to refer to Chart 8 instead of Chart 7.

This information has been corrected and is shown on the attached page.

RADIO/AUDIO SYSTEMS (ETR): UM6, UM7, U1C, AND U77 SYSTEM CHECK -------------------------------------------------------------- ACTION NORMAL RESULTS ------ -------------- (1)

o Put Ignition Switch in "ACCY" or "RUN." The display comes on.

o Turn the Radio on. The digital Clock operates.

(2)

o Operate Radio/Cassette/ Radio/Cassette/CD Player CD Player controls controls operate as described (see Section 8A for operation in Section 9A. information).

(3)

Light Switch to "PARK." Radio digital display dims. Radio face and buttons become illuminated.

(4)

o Adjust dimming control. Radio display, face and button illumination varies with dimming control.

SYMPTOM TABLE

SYMPTOM PROCEDURE PAGE NUMBER ------- --------- -----------

Radio does not appear to Chart #1 8A-150-5 operate (no display lights, no sound),

Vacuum flourescent display does Chart #2 8A-150-5 not dim, but Radio face and buttons are illuminated with Park or Headlights on.

Radio face and buttons are not Chart #3 8A-150-6 illuminated with Park Lights or Headlights on.

No sound comes from a Speaker Chart #4 8A-150-6

Radio appears to work (display Chart #5 8A-150-7 appears) but discrete audio information cannot be heard or no sound comes from any Speaker.

All stations are weak, noisy Chart #7 8A-150-8 (both AM and FM).

Weak, noisy (AM ONLY) Chart #7 8A-150-8

Weak, noisy (FM only, without Send the Radio to an Rear Defogger Antenna) authorized AC Delco repair station.

Weak, noisy (FM Only, with Rear Chart #7 8A-150-8 Defogge Antenna)

Noise present with Ignition Chart #7 8A-150-8 Switch in "RUN" engine not running

Harsh, popping noise that changes Chart #7 8A-150-8 with engine rpm (Ignition Noise)

High whine (like a siren) that Chart #7 8A-150-8 changes with engine rpm (Generator Noise)

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.