A/C - Inoperative, Code 09 (Low Freon)

Bulletin:
93-1-4

Date:
Dec. '92

Ref.No.:
93-63-1

Corp.Ref.No.:
231209



SUBJECT:
INOP A/C COMP. CLUTCH (DIAGNOSE/CUT WIRE/SMU - SECT. "1C")

MODELS AFFECTED:
1992-93 ROADMASTER AND ROADMASTER WAGON


1992 and '93 Roadmasters built before VIN PR404608, with the Electronic Air Conditioning Option (RPO C68).

NOTE:
This bulletin includes an update to the 1991-92 Service Manual Section 1C.

CONDITION:

The air conditioning (A/C) system may become inoperative when the air compressor clutch does not engage. This may also coincide with the "Degree F" or "Degree C" flashing and the "ECON" graphic illuminating on the Electronic Air Conditioning Control Display. A Diagnostic Trouble Code (DTC) 9 (low Freon) may also be stored in the microprocessor of the Air Conditioning Control Assembly.

CAUSE:

The above conditions will occur when the microprocessor in the Electronic Air Conditioning System detects low Freon. However, a false DTC 9 may be set if the A/C control relay, high pressure cutout switch, or pressure cycling switch operate intermittently.

CORRECTION:











A new diagnostic procedure (Pages 1C-26 and 1C-27 in the 1992 Buick Service Manual, and Page 1C1-24 in the 1991 Service Manual) should be used to diagnose the above condition. This diagnostic procedure will determine if a false DTC 9 was set and stored. After the new diagnostic procedure has been performed, if system checks O.K., the following steps should be performed to disable the low Freon detection system of the Electronic Air Conditioning Control, to prevent a false DTC 9 being set by the microprocessor.

NOTE:
This new procedure replaces "Figure 20 - Code 09 Low Freon Detected" in Section 1C of the Service Manual.



Low Freon detection will still be provided by the A/C Pressure Cycling Switch, as in the Manual Air Conditioning Systems. The DTC 9 must be cleared in order for the system to function properly.

To disable the Electronic Air Conditioning low Freon detection system:

1. Remove the lower passenger side hush panel.





2. Locate connector C205 (Figure 1).

3. Cut the wire (Lt. Blue) located in Pin K of connector C205 (Figure 1). Tape the cut wires back to the wire harness.

4. Reinstall lower hush panel.

WARRANTY INFORMATION:

Labor Operation No.: T1892
Labor Time: 0.9 HR.





This labor time includes diagnosis per chart (Figure 20). Refer to the appropriate Labor Code for replacement of any other component.