P0693 — Fan 2 Control Circuit Low #

Note: The wording of this code’s description may vary between manufacturers.

• “Fan 2 Control Circuit Low” (Generic/OEMs)
• “Secondary Cooling Fan Relay Control Circuit Low” (General Motors)
• “Radiator Fan 2 Control Circuit Low Input” (Ford)
• “Cooling Fan No.2 Circuit Low” (Toyota/Lexus)
• “Electric Fan 2 Control, Low Voltage” (Chrysler/Jeep/Dodge)

Summary of DTC P0693 #

P0693 is a generic OBD-II powertrain diagnostic trouble code (DTC) that indicates the Engine Control Module (ECM) has detected an abnormally low voltage or poor electrical performance in the secondary cooling fan control circuit. This means the circuit that controls the second (auxiliary) radiator fan is not functioning as expected. The ECM monitors this circuit’s voltage and current; if it sees a value below its programmed threshold, it triggers this code. Proper functioning of both cooling fans is crucial for managing engine temperature, especially under heavy load or in hot weather. Left unresolved, this code can lead to cooling issues and, in rare cases, engine overheating.

Common Symptoms for Code P0693 #

When P0693 is stored, you may notice your vehicle’s cooling system isn’t performing optimally. Symptoms can range from subtle to obvious, depending on climate, driving conditions, and whether your vehicle is idling or moving. Here’s what you might experience:

• Illuminated Check Engine Light
• Engine temperature gauge reading higher than normal
• Reduced air conditioning performance (especially at idle)
• Radiator fan 2 not running when expected
• Fan-related warning lights or messages on the dashboard (on some vehicles)
• Potential engine overheating during stop-and-go traffic or hot weather

Probable Causes for Code P0693 #

While electrical faults are the most common root of P0693, several other issues can trigger this code. The following causes are ranked from most to least likely:

1. Faulty cooling fan 2 relay (relay failure is the top culprit)
2. Blown fuse in the fan 2 circuit
3. Open, shorted, or corroded wiring/connectors in the fan 2 circuit
4. Failed fan motor (fan 2 itself)
5. Defective Engine Control Module (ECM) (rare)
6. Poor ground connection for the fan circuit

Step-by-Step Diagnostic for P0693 #

To accurately diagnose P0693, a systematic approach is essential. This process usually requires basic tools like a multimeter, test light, and a wiring diagram for your specific vehicle. Here’s a structured diagnostic guide:

• 1. Verify the code with a scan tool and check for any related codes (especially P0691, P0692, or other fan circuit codes).
• 2. Inspect the cooling fan 2 fuse(s) and replace if blown.
• 3. Locate and test the fan 2 relay by swapping with a known good relay (if possible) or testing for continuity and function.
• 4. Check wiring and connectors between ECM, fan relay, and fan motor for damage, corrosion, or loose connections. Repair as needed.
• 5. Test the fan motor by applying direct battery voltage to see if it runs (with relay/fuse removed).
• 6. If all components test good, check ECM outputs and grounds with a multimeter for proper voltage and continuity.
• 7. If no fault is found, suspect a rare ECM issue; verify with OEM-specific diagnostic procedures before replacing.

Likely Repairs for P0693 #

Once the root cause of P0693 is identified, targeted repairs restore proper cooling operation. Here’s what typically resolves this code:

• Replace the faulty fan 2 relay
• Replace blown fuse and address short circuit if found
• Repair or replace damaged wiring or corroded connectors
• Replace the fan 2 motor if it fails a direct voltage test
• Repair poor ground connections
• In rare cases, replace or reprogram the ECM (after all other causes are ruled out)

Is It Safe to Drive with Code P0693? #

Limited. You can generally drive short distances with P0693, but caution is advised. The second cooling fan is critical for high-load conditions (hot weather, traffic, towing, heavy AC use). If you notice rising engine temperatures or are planning city driving or long trips, repairs should be prioritized. Extended operation with a non-functioning fan can result in overheating and expensive engine damage.

Vehicles Most Affected by P0693 #

P0693 is a generic code but tends to appear most commonly on vehicles with dual electric fans and complex fan control logic. The following brands and models are frequently associated:

• Chevrolet/GMC (Silverado, Tahoe, Trailblazer)
• Ford (F-150, Explorer, Mustang)
• Toyota (Camry, Highlander, Tacoma)
• Chrysler/Jeep/Dodge (Grand Cherokee, Charger, Ram)
• Volkswagen/Audi (Passat, Jetta, Golf)
• Honda/Acura (Accord, Odyssey, Pilot)

Common Mistakes & Best Practices with P0693 #

Misdiagnosis is common with P0693 due to the number of components involved. Rushing or overlooking simple issues complicates repair. Follow these best practices:

• Don’t replace the fan motor without verifying relay/fuse and wiring first!
• Always inspect connectors for corrosion or loose pins—especially in humid climates.
• Consult the OEM wiring diagram for your specific vehicle model.
• After repair, clear the code and confirm proper fan operation with a scan tool and by running the vehicle to operating temperature.
• Test relays and fuses under load—not just for continuity.

Quick FAQ for Code P0693 #

Q: Can P0693 cause my car to overheat?
A: Yes, especially in stop-and-go traffic, hot weather, or when using the air conditioning. The secondary fan helps manage engine temperature under higher loads.

Q: Is P0693 expensive to repair?
A: Not usually. Most repairs (fuses, relays, or wiring) are inexpensive. The cost rises only if the fan motor or ECM is at fault.