What Does P1656 Mean?
The PCM has detected that the air conditioning clutch relay control circuit is shorted to ground. This prevents proper control of the A/C compressor clutch engagement.
Common Causes
35%
Chafed or damaged wiring causing short to ground in A/C clutch relay circuit
30%
Failed A/C clutch relay with internal short to ground
20%
Shorted A/C compressor clutch coil
15%
Corroded connectors or pins shorted to ground
Diagnostic Steps
1
Step 1: Locate A/C clutch relay and remove it from socket; check if code clears or remains
2
Step 2: Inspect relay socket terminals and wiring for signs of shorting, damage, or corrosion
3
Step 3: Test A/C clutch relay with multimeter for proper coil resistance and contact operation
4
Step 4: With relay removed, check resistance to ground on PCM control wire (should be high resistance/open)
5
Step 5: Trace wiring harness from relay to PCM and A/C compressor checking for chafing or pinch points
Estimated Repair Cost
$100 - $400
Parts + labor, varies by vehicle and location
The PCM has detected that the air conditioning clutch relay control circuit is shorted to ground. This prevents proper control of the A/C compressor clutch engagement.
The most common cause of P1656 (A/C clutch relay circuit short to ground) is: Chafed or damaged wiring causing short to ground in A/C clutch relay circuit
Typical repair costs for P1656 range from $100 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Air conditioning will not function, affecting driver comfort. No direct safety impact, though reduced visibility may occur if windshield defrost is needed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1656 to identify the root cause.
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Quick Info
Category
Powertrain
System
Air Conditioning System
Difficulty
Type
Manufacturer
Recommended Tools
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