0320394 JOHNSON CAM, Throttle control

Table 1
Diagnostic Trouble Codes
CDL Code Code Description Comments
485-5 Engine Fan Reversing Solenoid : Current Below Normal There is an open circuit in the wiring.
Or:
There is an open circuit inside the coil for the fan.
485-6 Engine Fan Reversing Solenoid : Current Above Normal This code is caused by a short circuit in the wiring between the P2 connector and the coils for the fan. The purpose of a reversing fan is to clean debris from the radiator. Temporarily reverse the direction of the air flow through the radiator fins in order to purge debris from the radiator fins. For some applications, the reversing fan is used to heat the engine compartment during cold-weather operation.In the automatic mode, the fan reversing solenoid is controlled by the Electronic Control Module (ECM). The ECM will automatically reverse the direction of the fan rotation. The ECM will use a preset time interval to cycle the fan reversing solenoid. The operator can manually reverse the fan rotation by pressing the engine fan reverse switch. While the momentary switch is depressed, the direction of the fan rotation will reverse. Once the switch is allowed to reset, the fan returns to normal operation and control of the fan will return to the automatic operation.
Illustration 1 g02904976
Schematic for the fan reversing solenoid
Illustration 2 g02167868
Table 2
Troubleshooting Test Steps Values Results
1. Verify Operation of the Engine Fan Reverse Switch
A. Connect the Cat® Electronic Technician (ET) to the service tool connector.
B. Turn the battery disconnect switch to the ON position.
C. Turn the keyswitch to the ON position.
D. Check the status of the engine fan reverse switch, on Cat ET while you operate the switch.
E. Turn the keyswitch