P0646
Air Conditioning Clutch Relay Circuit Low
Generic code
Computer Output Circuit
High severity
Hard repair
Free on OBD DashX
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What P0646 means
- The fault code P0646 indicates that there is an issue with the A/C clutch relay control circuit, which is operating at lower than the normal voltage levels. This may cause the A/C to stop working or work intermittently.
Possible symptoms
- A/C may not work or may work intermittently
- Illuminated A/C light on the dashboard
- Reduced fuel efficiency
- Illuminated check engine light
Possible causes
- Faulty A/C clutch relay
- Wiring or connections in the circuit that are damaged or corroded
- Loose or corroded electrical connections
- Failed engine control module (ECM)
Related parts
- AC Clutch Relay: The A/C clutch runs the A/C compressor. Problems lead to reduced or no AC cooling
Possible solutions
- Replace the A/C clutch relay
- Check and repair any damaged wiring or connections
- Tighten or clean any loose or corroded electrical connections
- Replace the engine control module (ECM) if necessary
Free on OBD DashX
P0646 on OBD DashX
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