P0645 - OBD II Trouble Code

Our automotive experts have put together the following information about the P0645 diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P0645 code.

What Does P0645 Code Mean?

OBD-II Code P0645 is defined as a A/C Clutch Relay Control Circuit

The engine control module (PCM) uses a relay to control voltage to the A/C Compressor Clutch. The A/C clutch engages, allowing the Air Conditioning system to operate. When the PCM is unable to control the relay, code P0645 will set.

P0645 Symptoms

• A/C may not operate

Common Problems That Trigger the P0645 Code

• A/C compressor failure
• A/C compressor relay failure
• Powertrain Control Module (PCM) failure
• Wiring issue

Common Repairs Needed for the P0645 Code

• AC Compressor Replacement