AutoCodes – Generic – P1484

P1484 Code - Cooling Fan RPM Signal Malfunction

Quick Answer

The engine cooling fan is a variable speed fan. Common causes include Faulty Fan Clutch Assembly, Fan Clutch Assembly harness is open or shorted, Fan Clutch Assembly circuit poor electrical connection. 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: P1484 indicates Cooling Fan RPM Signal Malfunction.
Common causes: Common causes include Faulty Fan Clutch Assembly, Fan Clutch Assembly harness is open or shorted, Fan Clutch Assembly circuit poor electrical connection.
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.

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Code Popularity 24,329

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 24, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code P1484 Description

The engine cooling fan is a variable speed fan. The Engine Control Module (ECM) controls the fan speed by sending a pulse width modulated signal to the cooling fan speed control module. The cooling fan control module varies the voltage drop across the engine cooling fan motor in relation to the pulse width modulated signal. The cooling fan speed is affected by many different conditions and can be adjusted from 10-90 percent duty cycle. Ninety percent is considered high fan speed. When multiple cooling speed requests are received, the ECM uses the highest cooling fan speed of all the requests. During normal fan ON operation, the control circuit voltage will be low and near battery voltage when the fan is OFF.

OBDII Code P1484 - Cooling Fan RPM Signal Malfunction - AutoCodes.com — P1484 Code - Cooling Fan RPM Signal Malfunction

What does this mean?

What are the Possible Causes of the DTC P1484?

Faulty Fan Clutch Assembly
Fan Clutch Assembly harness is open or shorted
Fan Clutch Assembly circuit poor electrical connection

How to Fix the DTC P1484?

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 P1484 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.

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Information for Specific Makes

P1484 Audi — Secondary Air Injection Pump Relay 2 Electrical Circuit Malfunction
P1484 Buick — Cooling Fan RPM Signal Malfunction
P1484 Cadillac — Cooling Fan RPM Signal Malfunction
P1484 Chevrolet — Cooling Fan RPM Signal Malfunction
P1484 Dodge — Trans Fan Relay Circuit
P1484 Ford — Open Power Ground To Variable Load Control Module
P1484 GMC — Cooling Fan RPM Signal Malfunction
P1484 Volkswagen — Secondary Air Injection Pump Relay 2 Electrical Circuit Malfunction

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.