P0485 Code - Cooling Fan Power/Ground Circuit Malfunction
Quick Answer
The electric cooling fan is controlled by the Engine Control Module (ECM) through the cooling fan relay based on inputs from the following components: - The engine coolant temperature (ECT) sensor - The intake air temperature (IAT) sensor - The A/C selector switch - The A/C refrigerant pressure sensor - The vehicle speed sensor (VSS) The ECM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. Common causes include Faulty fan control relay, Faulty cooling fan, Fan control relay harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P0485 indicates Cooling Fan Power/Ground Circuit Malfunction.
- Common causes
- Common causes include Faulty fan control relay, Faulty cooling fan, Fan control relay harness is open or shorted.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code P0485 Description
- The engine coolant temperature (ECT) sensor
- The intake air temperature (IAT) sensor
- The A/C selector switch
- The A/C refrigerant pressure sensor
- The vehicle speed sensor (VSS)
The ECM controls the cooling fan by grounding the cooling fan control circuit which turns ON the cooling fan relay. The cooling fan relay will be commanded ON when the following conditions are met:
- The engine coolant temperature reaches 106°C (223°F) or more.
- The A/C clutch requested.
- The vehicle speed is less than 38 MPH.
The cooling fan relay will be commanded ON regardless of vehicle speed when the following conditions are met:
- The engine coolant temperature is 151°C (304°F) or more.
- The A/C refrigerant pressure is high.
The cooling fan may be commanded ON when the engine is not running under a fan run-on conditions described in the electric cooling fan general description portion of the service manual.
What are the Possible Causes of the DTC P0485?
- Faulty fan control relay
- Faulty cooling fan
- Fan control relay harness is open or shorted
- Fan control relay circuit poor electrical connection
- Fan cooling fan harness is open or shorted
- Fan cooling fan circuit poor electrical connection
How to Fix the DTC P0485?
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 P0485 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.
Need more information about the P0485 code?
Need more information on how to fix the P0485 code? Get Access to Factory Service Manuals
Need Help with the Code?
Get the P0485 code diagnosed by a professional: Find a repair shop in your area
Information for Specific Makes
- P0485 Mazda — Cooling Fan Power/Ground Circuit Malfunction
- P0485 Mercedes-Benz — Cooling Fan Power/Ground Circuit Malfunction
Frequently Asked Questions about P0485 Code
No Frequently Asked Questions about P0485 Code found.
Discuss the causes and fixes for P0485 OBDII Code
Code P0485 comments
No comments found for this page.
Fix Your Car Smarter
Try the New AutoCodes App!
Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.
