Intermittent failure of Buick Regal air conditioning compressor and cruise function
  • Automotive

A Buick Regal car with a mileage of about 76 thousand km. Users reflect that the compressor and cruise function are intermittently invalid, the fault code is P0560 (low system voltage), and P1585 (cruising control device prohibits the output circuit). Maintenance process: 1) when the air conditioner is turned on, the compressor is regularly absorbed and disconnected, and the refrigerant pressure of the air conditioning system is measured to meet the standards. 2) the road test found that the cruise system was activated when the speed reached 40km/h, but sometimes the cruise automatically closed when the speed increased. The fault code P0560 can not be cleared. 3) observe the data, the ignition voltage in the Tech-2 list is 14.7V, and the output voltage of the generator is 14.7V with multimeter. In addition, refer to figure 1, check the grounding line of the whole vehicle, and all are connected and fastened. Troubleshooting: because the system voltage is normal and the fault code P0560 can not be cleared, PCM internal fault is suspected. Troubleshooting after replacing PCM. Circuit diagram shows: PCM monitors the system voltage of its ignition power supply circuit. If the voltage exceeds the tolerance, the fault code P0560 will be set up. When a fault code P0560 is set up, the operation of part of the system and parts of the vehicle will be affected.