Electronically Controlled Viscous Drive - Diesel

Fig 1: Electronically Controlled Viscous Fan Drive Connector Pin ID

Courtesy of CHRYSLER LLC

If the fan assembly does not free-wheel and a metallic grinding sound exists, replace the electronically controlled fan drive. Refer to FAN, Cooling, Electric, Removal  or FAN, Cooling, Viscous, Removal .

The engine should be at normal operating temperature.

1. Set the parking brake and verify the transmission is in park or neutral.
2. Set air conditioner (if equipped) and blower fan to OFF.
3. Start and allow engine to reach normal operating temperatures.
4. Stop engine, connect the scan tool and select appropriate model year and engine option.
5. Check for and correct existing DTC's
6. Locate the electronically controlled viscous fan drive connector on the fan shroud.
   WARNING:

   A spark may occur when the connection to battery is made. Be sure there are no combustible materials near the area where this procedure is being performed.

7. Using a jumper wire, backprobe pin 6 of the viscous fan drive connector to battery positive.
   NOTE:

   The fan drive control coil is energized to 12 volts at this time.

8. Using the scan tool, confirm that DTC 0480 is set to verify a good connection at the cooling fan harness connector.
9. Start the engine.
10. Actuate engine speed to 2000 RPM.
11. Go to the SENSOR screen and observe the fan speed.
12. Run the engine at 2000 RPM until the fan speed increases to 1850 RPM or more for 30 seconds.
    NOTE:

    Fan RPM may ramp up slowly.

    NOTE:

    It maybe take 15 minutes before fan speed increases.

13. The fan speed should be in accordance to the VISCOUS FAN DRIVE SPEEDS  table below.
14. If fan speed does not increase, make sure that the jumper wire has a good connection. If so replace the electronically control viscous fan drive.
15. If the fan speed does increase and there is still a concern, refer to the appropriate Engine Performance Electrical Diagnostics article to diagnosis the electronically controlled viscous fan drive control circuit.