Table 152
Diagnostic Codes for Cooling Fan Control
J1939 Code
Code Description
(code descriptions may vary)
Comments
4212-5
Engine Cooling Fan Solenoid : Current Below
Normal
The Electronic Control Module (ECM) detects an open circuit in the circuit
for the engine fan control solenoid.
The ECM sends minimum current to the fan control solenoid. The code is
logged.
4212-6
Engine Cooling Fan Solenoid : Current Above
Normal
The ECM detects a short circuit to ground in the circuit for the engine fan
control solenoid.
The ECM sends minimum current to the fan control solenoid. The code is
logged.
The ECM monitors engine coolant temperature,
intake manifold air temperature, and hydraulic oil
temperature. The ECM monitors the sensors to
determine the correct speed for the engine cooling
fan.
The ECM controls the speed of the fan by controlling
the current to the engine fan control solenoid. The
engine fan control solenoid controls the amount of
pressure to the fan motor by allowing oil to bypass
the fan motor. The fan pump drives the fan. When the
ECM outputs minimum current to the engine fan
control solenoid, less oil is bypassed. The fan motor
will now drive the fan at a higher rpm. When the ECM
outputs maximum current to the engine fan control
solenoid, more oil is bypassed. The fan motor will
now drive the fan at a lower rpm.
If the ECM detects a system fault, the ECM provides
minimum current to the solenoid. Minimum current
ensures a maximum fan speed while the fault
condition exists.
An override is available in the electronic service tool.
The override allows the fan to be manually changed
from the minimum to the maximum rpm.
During the following procedure, refer to the electrical
schematic for the application.
Complete the procedure in the order in which the
steps are listed.
UENR4469-36 279
Circuit Tests
Copyright of Perkins Engine Company Limited. NOT FOR REPRINTING OR RESALE
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