A/C - Inoperative/Code 578 and 579 Set

Article No.
93-5-8

March 3, 1993

^ AIR CONDITIONING - ENGINE COOLING FAN AT HIGH SPEED AT ALL TIMES WHEN A/C IS ON AND ERROR CODE 579 IS SET IN EEC MEMORY

^ AIR CONDITIONING - INOPERATIVE - NO VOLTAGE TO CLUTCH

^ AIR CONDITIONING - INOPERATIVE - NO VOLTAGE TO CLUTCH AND ERROR CODE 578 IS SET IN EEC MEMORY



LINCOLN-MERCURY: 1993 MARK VIII



ISSUE:
The air conditioning pressure sensor may not be connected properly, resulting in one of the following symptoms:

^ A/C does not operate and there is no voltage to the clutch.

^ A/C does not operate, there is no voltage to the clutch and Error Code 578 is set in the EEC memory.

^ A/C operates, but the engine cooling fan is at high speed at all times when the A/C is engaged. Error Code 579 is set in the EEC memory.

ACTION:
Check the connector at the A/C pressure for proper orientation and correct if necessary. Refer to the following procedure for service details.





1. Check the connector at the A/C pressure sensor for proper orientation as shown in Figure 1.

2. If the connector is 90~, 180~ or 270~ clockwise from the properly latched position, reconnect the electrical connector in the proper position.



3. Check the air conditioning operation.

4. If the system does not operate properly, replace the A/C pressure sensor (F3LY-19D594-A). Refer to the 1993 Mark VIII Service Manual, Section 12-03, for replacement procedure.

PART NUMBER PART NAME CLASS

F3LY-19D594-A A/C Pressure Sensor C

OTHER APPLICABLE ARTICLES: NONE

WARRANTY STATUS:
Eligible Under Bumper To Bumper Warranty Coverage

OPERATION DESCRIPTION TIME
930508A Inspect And Correct 0.3 Hr.
Orientation Of Switch Connector
930508B Inspect Switch Connector 0.4 Hr.
And Replace Switch

DEALER CODING
BASIC PART NO. CONDITION CODE
19D594 46

OASIS CODES:
208000, 208200, 402000