Vehicle Shifts Differently When A/C Is Engaged

When A/C is turned on, a dual pressure switch closes, introducing battery voltage to PCM signaling the system to increase oil pressure and shift points to compensate for the additional engine load. If this action does not occur, the following are possible causes for this condition:

• Faulty dual pressure switch.
• Damaged wire harness or connector.
• Faulty A/C system.
• Faulty PCM.