P0646 2014 Chevrolet Silverado Code - Air Conditioning Compressor Clutch Relay Control Circuit Low Voltage
Quick Answer
When the Air Conditioning (A/C) switch is pressed, the Heating, Ventilation, and Air Conditioning (HVAC) control module sends an A/C request message to the Engine Control Module (ECM) via serial data. Common causes include Faulty Air Conditioning (A/C) Compressor Clutch Relay, Air Conditioning Compressor Clutch Relay harness is open or shorted, Air Conditioning Compressor Clutch Relay circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
- What it means
- P0646 2014 Chevrolet Silverado indicates Air Conditioning Compressor Clutch Relay Control Circuit Low Voltage.
- Common causes
- Common causes include Faulty Air Conditioning (A/C) Compressor Clutch Relay, Air Conditioning Compressor Clutch Relay harness is open or shorted, Air Conditioning Compressor Clutch Relay circuit poor electrical connection.
- Severity
- Low - monitor the vehicle and repair when practical.
- Can I drive?
- The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
Code P0646 2014 Chevrolet Silverado Description
What are the Possible Causes of the DTC P0646 2014 Chevrolet Silverado?
- Faulty Air Conditioning (A/C) Compressor Clutch Relay
- Air Conditioning Compressor Clutch Relay harness is open or shorted
- Air Conditioning Compressor Clutch Relay circuit poor electrical connection
- Faulty Air Conditioning Compressor Clutch
- Faulty Engine Control Module (ECM)
How to Fix the DTC P0646 2014 Chevrolet Silverado?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0646 2014 Chevrolet Silverado code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0646 2014 Chevrolet Silverado Code
1. What does the OBDII code P0646 mean on a 2014 Chevrolet Silverado?
P0646 indicates a low voltage issue in the air conditioning compressor clutch relay control circuit, which can affect the operation of the A/C system.
2. What are the common symptoms of code P0646 on a 2014 Chevy Silverado?
Symptoms may include the air conditioning not working, reduced cooling performance, and the Check Engine Light being illuminated.
3. What causes the P0646 code on a 2014 Chevrolet Silverado?
Common causes include a faulty A/C compressor clutch relay, damaged wiring or connectors in the control circuit, or issues with the powertrain control module (PCM).
4. Can a bad A/C compressor cause the P0646 code?
Yes, a failing A/C compressor or clutch can sometimes trigger this code if it creates abnormal electrical resistance in the circuit.
5. How do I diagnose the P0646 code on my Chevy Silverado?
Start by inspecting the relay, wiring, and connectors for damage or corrosion. Use a multimeter to check for proper voltage and continuity in the circuit.
6. Is it safe to drive with the P0646 code on a 2014 Silverado?
Yes, it is generally safe to drive, but the A/C system may not function correctly, which can be uncomfortable in hot weather.
7. How can I fix the P0646 code on a 2014 Chevrolet Silverado?
Repairs may involve replacing the A/C compressor clutch relay, repairing damaged wiring, or in rare cases, reprogramming or replacing the PCM.
8. How much does it cost to fix the P0646 code on a Chevy Silverado?
Repair costs vary but typically range from $50-$300 depending on whether the issue is a simple relay replacement or involves extensive wiring repairs.
9. Will clearing the P0646 code make my A/C work again?
Clearing the code without addressing the underlying issue will not fix the problem, and the code is likely to return.
10. Can a blown fuse cause the P0646 code on a 2014 Silverado?
Yes, a blown fuse in the A/C system circuit can lead to low voltage and trigger the P0646 code. Always check the fuse box during diagnosis.
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