P0480 – Engine coolant blower motor 1 -circuit malfunction

By Patrick (Contact Me)
Last Updated 2016-03-21
Red Seal Certified Mechanic

Trouble CodeFault LocationProbable Cause
P0480 Engine coolant blower motor 1 -circuit malfunction Wiring, engine coolant blower motor, ECM

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What Does Code P0480 Mean?

When your car is idling at a stop sign for a while there is no cool air passing through the fins of your radiator this means the temperature within the cooling system will rise. This is a problem because the cooling system is responsible for regulating your engines temperature. Thankfully, auto makers had that in mind when adding a cooling fan(s) to the radiator, which in turn blows air through the fins of the radiator, mimicking the air that would typically pass through while driving at any speed. In earlier makes and models, the cooling fan was mechanically connected to the engine. Most of the latest makes and models have electronically operated cooling fans with no mechanical connection to the engine. Generally speaking , there are 2 relays that control your cooling fans, the low speed relay and the high speed relay. The PCM energizes these relays based on your engines cooling needs. The cooling fan relay 1 control circuit is responsible for controlling the low speed of these cooling fans. The PCM detects issues within the system and will display check engine light on the instrument cluster the moment values within the circuit go beyond operating parameters. If this code is active, more then likely your cooling fan(s) will not come on at one or any speeds.

What are the common causes of code P0480 ?

  • Defective cooling fan (s)

  • Defective cooling fan relay (s)

  • Corroded or chafed wires within relay control circuit

  • Corroded or loose connections

  • Low system voltage

  • Defective PCM

What are the symptoms of code P0480 ?

When this particular code is active you may or may not experience some of the following symptoms:

  • Overheating (specifically, while idling for long periods of time)

  • Cooling fan(s) inoperative

  • Low vehicle power

  • Erratic engine operating temperatures

How do you troubleshoot code P0480 ?


Whenever you are working with cooling system electrical components and systems, some of the basic tools you will need are:

  • OBD code reader

  • Multimeter

  • Basic socket set

  • Basic ratchet and wrench sets

  • Basic screwdriver set

  • Rag/shop towels

  • Battery terminal cleaner

  • Wheel chalks


Whenever performing repairs of any kind to your vehicle, you must follow certain steps to keep you safe:

  • Wear PPE (Personal protective equipment)

  • Chalk wheels to prevent rollaway.

  • Park vehicle on flat and level surface


Check your battery! If you have a problem with your battery system, your vehicle can do some funny things and throw codes for systems that aren’t necessarily malfunctioning. Visually inspect terminals, wires and battery body for signs of damage or corrosion. If battery acid present, sprinkle baking soda and water on affected area, wipe with old rag and discard appropriately. Don’t forget rubber gloves! Battery acid will burn your skin!. Perform basic electrical test as follows: Connect your red positive multimeter end to (+) battery post and your black ground multimeter end to (-) battery post and measure voltage. With engine shut off you will want a voltage between 11.7v – 12.6v. With engine running, you will want a voltage between 13.5v -14.5v. If your values aren’t within these specifications, the problem may lie within your battery and/or charging systems and will need to be addressed. If they are, proceed to next step.

NOTE: Visually inspect all ground straps and look for corroded or loose ground connections.


Check all fuse(s) and relay(s) related to the cooling fan control circuits. For the most part, the fuse box will be under hood somewhere or under dash (refer to service manual for specific locations and specific procedures). Often times the coolant power relay itself may be mounted on the radiator itself Replace any blown fuses or relays which may show signs of overheating (burnt smell, melting). Clean any corrosion present. Clear codes using code reader and test drive. If code reappears or if fuse(s) and relay(s) are good, proceed to next step.

NOTE: Make sure to disconnect battery before performing any electrical repairs.


Pop the hood and locate your cooling fan assembly. Once located, look for any signs of physical damage. If everything looks good, look at the electrical connections themselves for signs of loose connections or corrosion around the plug(s). Its a good idea to identify the wiring harness and follow it as far as you can, inspecting for chafes or cuts in wires themselves. Most of the time, wiring issues like these are difficult to pinpoint. Perform any necessary repairs, clear codes and test drive vehicle.


Check for continuity. Refer to service manuals (i.e Haynes, Bentley etc..) to find wiring diagram for this circuit. Using the colour codes within diagram, pinpoint wires at relay and PCM connectors. Unplug connectors at both ends. Using your multimeter, measure the resistance in the wires involved and check for short to power or ground. If values are within manufacturers specifications, proceed to next step.


Depending on the capabilities of your OBDII scan tool, you may be able to remotely turn on/off the cooling fan relay. If so, try turning it on/off listening for an audible click. Hearing the click means the relay is activating. At this point it is likely the relay is functioning as it should. If there is no click coming from the relay, try replacing the relay with new one. Clear codes, and test drive vehicle. If the problem persists, bring to reputable repair facility as you may have a problem worthy of a trained eye!

Codes Related to P0480

  • P0481 – Cooling fan relay 2 control circuit.

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