B446,B447 & B448 CODE DIAGNOSIS (REPLACE PROM)

SUBJECT: B446, b447 AND B448 CODE DIAGNOSIS

MODELS AFFECTED: 1986-1990 ELDORADOS AND SEVILLES

Some 1986-1990 Eldorados and Sevilles may experience low refrigerant codes showing a code B446, codes B446 and B447, or code B448. To diagnose and repair these conditions follow the appropriate trouble tree in Figure 1, Figure 2, and/or Figure 3. On 1988-1990 vehicles a premature low refrigerant code B446/B447 may be displayed in cool ambients (45* - 65' F). This condition can be repaired by following the trouble tree (Figure 1) for diagnosis and, if necessary, replacing the PROM in accordance with the chart below:

PROM CHART

ORIGINAL PROM I.D. NEW PROM I.D.

Broadcast PROM Broadcast Code I.D. Code I.D. P/N ------ ----- ------- ---- -------- 1988 AJUT 0186 AUPL 1996 16151993 ANUD 8256 ASCD 9066

1989 ANDP 3776 AUKN 1046 16151037 APYK 3426 ASAP 8766 ATPU 5916

1990 ANXX 9236 AUKP 1056 16151314

NOTE: Failure to recover, evacuate, and recharge with the proper amount of refrigerant may result in recurrence of low refrigerant indicator.

WARRANTY INFORMATION VEHICLE SERIES Operation Operation Description Number C D E J K V -------------- -------- -- -- -- -- -- -- PROM, Replace N4801 .5 .5

BCM, Replace N4800 .5 .5

Wiring/Connector N6030 .5 .5 Repair

Low Refrigerant D1130 .2 .2 Pressure Switch, Replace A/C Leak Test D3000 .3 .3

NOTE: Add .7 hour for recovery, evacuation, and recharge of A/C system when necessary.

Parts are currently available from GMSPO.

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.