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Coolant fan not coming on

Rocketst

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Location
Chesapeake, VA, USA
#1
So I've been getting this code intermittently. Is there a way to check with forscan what's causing this code? The code is a p0480. Intermittent failures are things that can't fail more than once so.... I can rule out fuse or relay right? This thing has 2 relays I think, 1 when temp reaching 210 and then one when ac clutch is on, or is that a switch? I've got a mountune radiator, 160 degree thermostat and running yellow coolant.

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SteveS

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Osage Beach, MO, USA
#2
No personal experience, but:
What causes the P0480 code?

  • Faulty cooling fan 1
  • Poor electrical connection in the fan circuit
  • Failed fan control relay has failed
  • Failed coolant temperature sensor
  • Faulty AC pressure switch
  • VSS not operating properly
How does a mechanic diagnose the P0480 code?

  • Uses a scan tool and checks for any codes stored in the ECU
  • Notes the freeze frame data that shows the coolant temp, RPM, vehicle speed, and etc. from when the code was set
  • Clears all of the codes
  • Takes the vehicle on a test drive and attempts to duplicate the conditions from the freeze frame data
  • Performs a visual inspection of the the fan system, checks carefully for fan operation and looks for damaged or worn wiring
  • Uses the scan tool to look at the datastream and confirms that the VSS sensor has proper readings, and that the coolant temperature sensor is reading accurately
  • Uses a relay tester to test the fan control relay or switches the relay with a good relay to test
  • Checks for proper operation of the AC pressure switch and that it is reading within specifications
Common mistakes when diagnosing the P0480 code

Mistakes are made when step by step diagnosis is not performed or steps are skipped entirely. There are many systems that may be responsible for the P0480 code and if they are overlooked the fan may be replaced when it was really the coolant temp sensor causing the fans not to operate.

What repairs can fix the P0480 code?

  • Replacing the VSS sensor
  • Replacing the engine coolant temp sensor
  • Repairing or replacing of the fan wiring harness
  • Replacing cooling fan 1
  • Repairing electrical connection issues
  • Replacing AC pressure switch
  • Replacing the fan control relay
 




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