KH: Hydraulic Cooling Fan

KH: Introduction See: KH: Hydraulic Cooling Fan - Introduction

KH1 DTC P1474 OR COOLING FAN CONCERNS: CHECK HCF SOLENOID RESISTANCE

• Key off.
• Disconnect HCF solenoid.
• Measure HCF solenoid resistance.

Is resistance between 8.5 and 11.5 ohms?
Yes

• GO to KH2

.

No

• REPLACE HCF solenoid assembly.

KH2 CHECK VPWR VOLTAGE TO HCF SOLENOID

• Key on.
• Measure VPWR circuit voltage at HCF solenoid.

Is voltage greater than 10.5 volts?
Yes

• KEY OFF. GO to KH3

.

No

• REPAIR open circuit.

KH3 CHECK HCF CIRCUIT FOR OPEN IN HARNESS

• Measure resistance of HCF circuit between PCM harness connector and HCF solenoid harness connector.

Is resistance less than 5 ohms?
Yes

• GO to KH4

.

No

• REPAIR open circuit.

KH4 CHECK HCF CIRCUIT FOR SHORT TO POWER IN HARNESS

• Key on.
• Measure voltage between HCF circuit at the PCM harness connector and ground.

Is voltage less than 1.0 volt?
Yes

• KEY OFF. GO to KH5

.

No

• REPAIR short circuit.

KH5 CHECK HCF CIRCUIT FOR SHORT TO GROUND IN HARNESS

• Disconnect scan tool from DLC.
• Measure resistance between HCF circuit at the PCM harness connector and ground.

Is resistance greater than 10,000 ohms?
Yes

• REFER to Engine Cooling. If OK, REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM

).

No

• REPAIR short circuit.