For PWM control, see Electric waterpump control (PWM).
See also, PWM CAN Module.
Water pump control, used when a relay is connected to MaxxECU output to control an electrical waterpump.
The output is pulsed on/off before the set temperature is reached to circulate the coolant liquid to avoid hot spots.
At low temperatures, the pulses are short, as the temperature increases the pulses get more frequent.
6 degrees below the set temperature the output is fully on.
Waterpump control
Target temperature
Specifies the target and desired coolant temperature (CLT).
Control band
If CLT changes is within the control dead band value, the output PWM duty is not changed.
Warmup
warmup method
•On/Off - Pulses the pump at the Warmup Duty to prevent hot spots.
•Constant duty - Uses the Warmup Duty until the engine is within 10C of the desired operating temperature.
Note: There is a 300 second warmup timeout, when passed, the control id disabled.
off below CLT
Turns the output off if the coolant temperature is below the threshold. Can be used to prevent pump damage due to freezing.
off below CLT, engine not running
Turns the output off if the coolant temperature is below the threshold when the engine is not running.
bleeding
Forces coolant circulation in a service/bleed mode to purge trapped air after coolant work.
Press the start/stop bleeding routine buttons to engage the bleed sequence and override normal pump control.
The water pump bleed function is a service mode that runs the pump through a timed duty-cycle pattern to purge air from the cooling system. When activated, normal pump control is overridden and pumpTargetDuty follows a predefined table of time points and duty values.
The sequence alternates between full speed, off, and partial speeds to generate flow pulses that move air pockets toward the expansion tank. The interpolation routine ensures smooth transitions between duty steps.
The routine stops automatically after about five minutes or if the engine is started (>500 rpm), returning control to normal cooling operation.
