Cooling Fan Speed Sensor Circuit Malfunction (GM)
What does P1480 mean?
The P1480 code means the vehicle's onboard diagnostic system has detected: Cooling Fan Speed Sensor Circuit Malfunction (GM). This is a moderate severity code.
Common Symptoms
- Check Engine Light illuminated
- Cooling fan may run at incorrect speed
- Engine temperature slightly higher than normal
- Fan may run continuously at maximum speed
- AC system performance reduced
Probable Causes (Ranked by Likelihood)
- Faulty cooling fan speed sensor Very High
- Damaged wiring to the fan speed sensor High
- Corroded connector at the fan module Moderate
- Failed cooling fan control module Moderate
- PCM input circuit fault Low
Step-by-Step Diagnostic Procedure
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Read the fan speed sensor data on a scan tool and compare to actual fan operation.
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Inspect the fan speed sensor connector for corrosion, water intrusion, or bent pins.
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Test the sensor signal wire for proper voltage output while the fan is running.
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Check the cooling fan control module for proper operation using manufacturer test procedures.
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Verify wiring continuity between the sensor and PCM.
Frequently Asked Questions
Why does my fan run at full speed all the time?
When the fan speed sensor fails, the PCM may default to running the fan at maximum speed as a safety measure. This protects the engine from overheating but increases fan noise and electrical load.
Where is the fan speed sensor located?
On most GM vehicles, the fan speed sensor is built into the cooling fan module or mounted near the fan motor. Accessing it may require removing the fan shroud.
Can a fan control module cause this code?
Yes. The fan control module regulates fan speed and contains the feedback circuit. If the module fails, it may not send the correct speed signal back to the PCM.