ELECTRICAL FAN CONTROL [SKYACTIV-G 2.0]
id0140f4205000
Outline
• Through cooling of the radiator and condenser by operation of the cooling fan according to vehicle conditions, engine reliability and cooling performance have been improved.
• The PCM determines the engine operation conditions based on the signal from each input part and controls the cooling fan motor operation time period and rotation speed by fan control module.
Block Diagram
Operation
Normal Driving Cooling Control
-
• Controls the PCM output duty ratio according to the engine coolant temperature.
• The control temperature while the engine coolant temperature is decreasing is controlled differently than when it is increasing.
When the A/C Signal is ON
-
• Controls the PCM output duty ratio depending on the refrigerant pressure and vehicle speed when the A/C switch is on.
Duty ratio (%)
|
Condition
|
Refrigerant pressure (Mpa {kgf/cm2, psi})
|
|
Below 1.18 {12.0, 171}
|
1.52 {15.5, 220}
|
Above 1.96 {20.0, 284}
|
|
Vehicle speed
(km/h {mph})
|
0
|
48
|
70
|
70
|
|
30 {19}
|
45
|
54
|
70
|
|
40 {25}
|
45
|
54
|
70
|
|
50 {31}
|
45
|
54
|
70
|
|
60 {37}
|
0
|
0
|
70
|
|
70 {43}
|
0
|
0
|
60
|
|
80 {50}
|
0
|
0
|
60
|
|
Above 90 {56}
|
0
|
0
|
0
|
Part protection conditions
-
• When the following conditions are met, the PCM drives the cooling fan at a duty value of 90%.
-
― Ignition switched ON
― Estimated part temperature is specified value or more (determines possibility of part damage from high temperature)
After Cooling Control
-
• If the ignition is switched off directly after continuous high engine-load travel, the PCM operates the cooling fan for a maximum of 9 minutes when all of the following conditions are met due to the possibility that the engine may not restart as a result of a fuel supply malfunction caused by the high temperature.
-
― Engine coolant temperature: 90°C {194 °F} or more
― Estimated coolant temperature after engine stop: 125°C {257 °F} or more
― Driving record for vehicle speed of 25 km/h {16 mph} or more available
During Test Mode
-
• Turn on the test mode using the Mazda Modular Diagnostic System (M-MDS), and with the accelerator pedal depressed, the PCM fixes the control duty ratio at the maximum value.
Fail-safe
-
• If the engine coolant temperature sensor is damaged, the PCM fixes the control duty ratio at the maximum value.
