AutoCodes – GMC – P1484 GMC

P1484 GMC 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 GMC 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 16,737

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
FAQs
Comments
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Code P1484 GMC 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 GMC - Cooling Fan RPM Signal Malfunction - AutoCodes.com — P1484 GMC Code - Cooling Fan RPM Signal Malfunction

What does this mean?

What are the Possible Causes of the DTC P1484 GMC?

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 GMC?

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 GMC 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 P1484 GMC code?

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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.

Frequently Asked Questions about P1484 GMC Code

1. What does the OBDII code P1484 mean on a GMC vehicle?

P1484 indicates a Cooling Fan RPM Signal Malfunction, meaning the PCM is not receiving the expected signal from the cooling fan regarding its rotational speed.

2. What are the common symptoms of code P1484 on a GMC?

Symptoms include engine overheating, cooling fan not operating properly, the Check Engine Light turning on, and potential reduced engine performance.

3. What causes the P1484 code on a GMC?

Common causes include a faulty cooling fan motor, damaged fan RPM sensor, wiring issues like shorts or open circuits, corroded connectors, or a malfunctioning PCM.

4. Can I continue driving my GMC with a P1484 code?

It is not recommended to drive with this code active, especially if the engine is overheating, as it could lead to severe engine damage.

5. How can I diagnose a P1484 code on a GMC?

Diagnosis involves inspecting the cooling fan and RPM sensor for damage, checking wiring and connections for continuity, and using a scan tool to monitor fan signal readings.

6. How do I fix the P1484 code on a GMC?

Repairs may include replacing the cooling fan motor or RPM sensor, repairing or replacing damaged wiring, cleaning corroded connectors, or, in rare cases, replacing the PCM.

7. Can a bad cooling fan cause the P1484 code?

Yes, a defective cooling fan motor or its integrated RPM sensor can trigger the P1484 code.

8. How much does it cost to fix a P1484 code on a GMC?

Repair costs vary depending on the issue, typically ranging from $150 to $600 for parts and labor, depending on whether the fan assembly or wiring needs replacement.

9. What tools are needed to address a P1484 code on a GMC?

You may need a scan tool to read and clear the code, a multimeter to test wiring, and basic hand tools for removing and replacing components.

10. Can a P1484 code cause engine overheating?

Yes, if the cooling fan isn't functioning correctly, it can lead to insufficient cooling and cause the engine to overheat.

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