P1484 CADILLAC – Cooling Fan RPM Signal Malfunction

P1484 CADILLAC Possible Symptoms

Engine Light ON (or Service Engine Soon Warning Light)

P1484 CADILLAC Possible Causes

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

P1484 CADILLAC 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.