Fleetwood Brougham V8-307 5.0L (1989)
PROM - Programmable Read Only Memory: All Technical Service Bulletins
A/C - Insufficient Cooling While Driving
Bulletin No.
T-89-39
File in Group
1
Number
58
Corp. Ref. No.
811212
Date
Nov. 1988
SUBJECT:
INSUFFICIENT A/C COOLING WHILE DRIVING
MODELS AFFECTED:
1988-1989 BROUGHAMS
Some 1988-1989 Broughams may experience a condition of insufficient A/C cooling while driving in stop-and-go traffic in hot, humid climates. This
condition may be caused by the ECM PROM calibration. The production calibration disengages the A/C compressor clutch with changes in throttle
angle, instead of only during a wide open throttle maneuver (as in past model years).
Should the insufficient A/C cooling only occur at an extended idle, refer to Serviceman Bulletin T-88-131.
To repair a condition of insufficient cooling in stop-and-go traffic use the following procedure:
1.
Verify that the A/C system has the proper charge of Refrigerant 12. With ambient temperature above 60~F:
^
Start engine and allow to warm up.
^
Open hood and body doors.
^
Set CCP at 60~F and "auto" setting.
^
"Hand feel" the temperature of the evaporator inlet pipe after the orifice tube and accumulator surface with the compressor engaged.
^
The temperature of both should be the same and both should be the same amount cooler than the ambient temperature.
^
If not, refer to Section 1C of the Service Information Manual for diagnosis.
2.
Install a scan tool and record the ECM PROM I.D. If the ECM PROM I.D. is 7524 (Federal) or 7528 (California), install the revised ECM PROM
from the chart below:
Emission
Service
Year
System
MEM-CAL PN
1988-1989
Federal
16122177
1988-1989
California
16132056
3.
If the condition is still present after installing the MEM-CAL, refer to ECC Functional Test in Section 1C of the 1988 or 1989 Service Information
Manual.
For warranty purposes use Labor Operation J6364 at .6 hour.
