P0644 Buick Driver Display Serial Communication Circuit

P0645 Buick Air Conditioning Clutch Relay Circuit Malfunction

Possible causes
– Faulty Air Conditioning Clutch Relay
– Air Conditioning Clutch Relay harness is open or shorted
– Air Conditioning Clutch Relay circuit poor electrical connection
What about the obd code?
The P0645 Buick code is stored if an open or short exists in A/C clutch relay control circuit.
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0645 Buick Description

A/C clutch relay may also be referred to as A/C compressor clutch relay. A/C clutch relay circuit is monitored when ignition is on and battery voltage is greater than 10.4 volts.

Buick Vehicle:Buick Regal – ?Buick Riviera – ?Buick LaCrosse – ?David Dunbar Buick – Buick Century – Buick LaCrosse – Buick LeSabre – Buick Lucerne – Buick Park Avenue – Buick Regal – Buick Verano – Buick Enclave – Buick Encore – Buick Rainier – Buick Rendezvous – Buick Terraza – Buick Riviera