What Does P1566 Mean?
The engine control module detects an unusual or inconsistent load signal from the A/C compressor clutch circuit. The signal voltage or pattern falls outside expected parameters during A/C operation.
Common Causes
35%
Faulty A/C compressor clutch or internal compressor mechanical failure
30%
Damaged wiring or poor connections in A/C clutch circuit
20%
Defective A/C pressure switch or transducer
15%
Failing PCM/ECM unable to properly interpret load signal
Diagnostic Steps
1
Step 1: Monitor A/C clutch engagement and load signal with scan tool while cycling A/C on/off
2
Step 2: Inspect wiring and connectors at A/C compressor clutch for damage, corrosion, or looseness
3
Step 3: Test A/C clutch resistance and check for proper voltage supply when engaged
4
Step 4: Verify A/C system pressures are within specifications using manifold gauges
5
Step 5: Check for mechanical binding or seized A/C compressor by rotating clutch manually
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
The engine control module detects an unusual or inconsistent load signal from the A/C compressor clutch circuit. The signal voltage or pattern falls outside expected parameters during A/C operation.
The most common cause of P1566 (Load signal from A/C compressor range/performance) is: Faulty A/C compressor clutch or internal compressor mechanical failure
Typical repair costs for P1566 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No direct safety concern. Vehicle remains drivable but A/C performance may be affected or engine idle quality may fluctuate.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1566 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Powertrain
System
Climate Control / Engine Management
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
