OBD2 P0645: A/C Clutch Relay Control Circuit

Error code

OBD2P0645

Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

A/C Clutch Relay Control Circuit.

moderateCan drive but may experience discomfort due to lack of air conditioning.

P0645 indicates an issue with the A/C clutch relay control circuit, which is part of the air conditioning system's electrical controls.

Stored trouble code and possibly an illuminated A/C-related warning light or message in the instrument cluster
The A/C system may not work or only function intermittently
Parts of some fuse boxes may show signs of overheating or melting
Internal blower motor may not work even if the A/C is not activated

Low A/C system pressure
Defective or failing A/C system pressure switches
Faulty clutch control relay
Damaged, burnt, shorted, corroded, or disconnected wiring and connectors in the low-amperage control circuit
Blown fuses or fusible links in the low-amperage control circuit

Check A/C system pressure and ensure all switches are functioning properly
Inspect the clutch control relay for signs of damage or failure
Examine wiring and connectors in the low-amperage control circuit for any issues

Replace faulty components such as the A/C system pressure switches, clutch control relay, or damaged wiring/connectors.

What does P0645 mean?

P0645 indicates a problem with the low-amperage circuit that controls the A/C clutch relay.

Where is the A/C clutch relay located?

The A/C clutch relay is usually found in the engine compartment's fuse box, often near other relays and fuses.

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.