P0482 OBD-II Trouble Code: Cooling Fan 3 Control Circuit Malfunction

P0482 code definition

The P0482 code is indicative of cooling fan 3 control circuit malfunction. Concurrent codes may be present, such as P0480, P0481, P0482, P1474, P1477 and/or P1479. If such codes are stored along with P0482, each one should be addressed in the order the event occurred.

What the P0482 code means

The electric cooling fan is a crucial element in keeping a vehicle’s engine from overheating. Some vehicles have two or three cooling fans, and in this case, the involved control circuit is that which operates fan #3. This code indicates that the PCM (powertrain control module) has detected voltage in the cooling fan control circuit outside of the normal parameters.

What causes the P0482 code?

The electrical system which controls the cooling fan circuits is made up of multiple components, which means that there could be a number of different causes for P0482 to set in a vehicle:

• Faulty cooling fan motor
• Faulty cooling fan motor relay
• Damaged or loose connectors or wiring
• Faulty engine coolant temperature sensor

What are the symptoms of the P0482 code?

Symptoms of this code may include an illuminated Service Engine Soon warning light, and as the problem progresses overheating and insufficient air conditioning function may occur.

How does a mechanic diagnose the P0482 code?

Diagnosing a problem within the cooling fan’s electric circuit involves not only visual inspection, but testing of the circuitry, sensors, and relay as well. Diagnostic steps may include:

• Connecting the vehicle to an OBD-II scanner to determine whether the code is stored, and check for other fault codes; if there are accompanying codes, these should be diagnosed and repaired in the order in which they occurred.
• Checking the voltage to the LFC (low-speed fan control) relay
• Testing for LFC circuit cycling
• Testing the LFC circuit for a voltage short, short to ground, or open in the harness
• Testing the voltage to the MFC (medium-speed fan control) relay
• Checking for MFC circuit cycling
• Checking for a short to voltage, short to ground, or open in the harness of the MFC circuit
• Checking the voltage to the HFC (high-speed fan control) relay
• Testing for HFC circuit cycling
• Checking the HFC circuit for a voltage short, short to ground, or open in the harness
• Testing the relays and circuits of the remaining fans

After completion of each step, the code will be cleared the vehicle retested to see if it returns.

Common mistakes when diagnosing the P0482 code

One of the most common mistakes when diagnosing this problem is replacing the fan motor without carrying out a thorough investigation of all of the other components. Cooling fan relays are a frequent source of this type of fault code and have been involved in multiple recalls.

How serious is the P0482 code?

While the issue may not seem pressing at first, any fault in the cooling system of a vehicle can result in catastrophic engine damage if not addressed promptly.

What repairs can fix the P0482 code?

Possible repairs for this code may include:

• Repair or replacement of wiring, connectors, or other circuitry components
• Replacement of fuses
• Cooling fan relay replacement
• Fan speed sensor replacement

Additional comments for consideration regarding the P0482 code

Because the cooling fan circuitry consists of such a complex network of wires, connectors, relays, sensors, and other components, locating and repairing the problem can be a lengthy, complicated undertaking best completed by a professional with the proper tools. In some vehicles the fan motors are driven by hydraulic pressure provided by the steering pump. Due to this set-up, any power steering leaks or other issues should be repaired before addressing the cooling fan fault.

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