Diagnostic Aids

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Perform this test only when instructed during QUICK TEST or if directed by other test procedures. This test is only intended to diagnose the following:

Wiring Harness Circuits (VPWR & HCF)
Hydraulic Cooling Fan Solenoid/Pump Assembly, See Fig 1
Powertrain Control Module (PCM)

Fig 1: Identifying Hydraulic Cooling Fan Solenoid/Pump

Courtesy of FORD MOTOR CO.

NOTE: Perform test step 1) when directed from ELECTRIC COOLING FAN DOES NOT OPERATE or ELECTRIC COOLING FAN ALWAYS ON symptom under SYMPTOMS in TROUBLE SHOOTING - NO CODES - EEC-V (GASOLINE) article.

1) DTC P1474 Or Cooling Fan Problems: Check HCF Solenoid Resistance
DTC P1474 is set when PCM detects voltage too high or too low when compared to expected voltage range on HCF primary circuit. Possible causes are:
- HCF Circuit Open, Or Shorted To Ground Or Power
- Faulty HCF Solenoid
- Faulty PCM
Turn ignition switch to OFF position. Disconnect HCF solenoid connector. Using a DVOM, measure resistance between HCF solenoid connector terminals. If resistance is 8.5-11.5 ohms, go to next step. If resistance is not 8.5-11.5 ohms, replace HCF solenoid assembly.

2) Check VPWR Voltage

Turn ignition switch to ON position. Measure voltage between HCF solenoid connector VPWR terminal and ground. See Fig 2. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open VPWR circuit.

Fig 2: Identifying Hydraulic Cooling Fan Solenoid Circuit & Connector Terminals
Courtesy of FORD MOTOR CO.

3) Check HCF Circuit For Open In Harness

Turn ignition switch to OFF position. Disconnect PCM harness connector "C". See Figure. Measure resistance of HCF circuit between PCM harness connector terminal C36 and HCF solenoid connector HCF terminal. If resistance is less than 5 ohms, go to next step. If resistance is more than 5 ohms, repair open HCF circuit.

4) Check HCF Circuit For Short To Power In Harness

Turn ignition switch to ON position. Measure voltage between PCM harness connector terminal C36 and ground. If voltage is less than one volt, go to next step. If voltage is one volt or more, repair short to power in HCF circuit.

5) Check HCF Circuit For Short To Ground In Harness

Turn ignition switch to OFF position. Disconnect scan tool from DLC. Using a DVOM, measure resistance between chassis ground and PCM harness connector terminal C36 (HCF circuit). If resistance is more than 10 k/ohms, replace PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article. Program PCM. See FLASH VEHICLE IDENTIFICATION (VID) BLOCK PROCEDURE . If resistance is 10 k/ohms or less, repair short to ground.