The Nissan Leaf coolant pump, which appears to be the same unit used in several Tesla EVs, circulates coolant through the cooling loop for the motor, inverter and PDM and the radiator. Compared to an ICE waterpump that is often belt-driven from the crankshaft, this one is electrically driven and controlled.
Connector
The pump connector is a Sumitomo 6189-1105.
| Pin | Function |
|---|---|
| 1 | +12 V |
| 2 | GND |
| 3 | PWM in |
| 4 | RPM out |
Electrical
The pump draws about TBD A from the +12 V feed at full load.
Control
Though main power is provided through the 12 V feed, the pump is controlled and monitored through two 5 V signal lines.
PWM input
| Pulse width | RPM |
|---|---|
| < 8 % | Invalid |
| 8–12 % | Off (0 rpm) |
| 13–17 % | Invalid |
| 18–82 % | Linearly increasing (750 – 4700 rpm) |
| > 83 % | Invalid |
RPM output
The waterpump has an RPM output giving a 5 V pulse every TBD rotation.