Tesla Model S/X Coolant Pump
Overview
Both the Model S and X use a very capable (but curiously unbranded) coolant pump. Internet research seems to indicate it may be made by VariMax[1], though there are so many Tesla part numbers it's hard to say which actual model it is.
In ICE circles, this pump is commonly used in high performance intercooler systems, so Lingenfelter Performance Engineering has compiled a fairly thorough (though questionably formatted) datasheet on the pump. Another fairly thorough overview can be found within the EV Create overview of the Tesla cooling system[2].
Specs
Some basic specs for the pump are as follows[1]:
- Target flow rate 720 LPH @ 70 kPa
- Inlet / Outlet connection: 19 MM Barb
- Motor syle: Brushless
- Operating voltage: 8-16 VDC
- Maximum amp draw: 7.3 Amp
Control
The pump can be controlled using PWM. The PWM voltage is 5V and the frequency is a rather unusual 2Hz. The pump speed can be controlled from ~750RPM at 20% duty cycle to ~5000RPM at 80% duty cycle.
Wiring
Connector
The pump has a single 4-pin plug which contains both the power and control signals. The plug itself is Sumitomo “RS” series:
- socket (female): 6189-7757
- retainer: 6918-1599
- pins (female): 8240-0263 (0.3-0.5mm2/24-20ga), 8240-0264 (0.85-1.25mm2/20-18ga), 8240-0265 (2.0mm2/16-14ga)
- seals (cable OD): 7165-0474 (1.0-1.4mm), 7165-0473 (1.5-1.9), 7165-0472 (2.0-2.4), 7165-0471 (2.5-2.9/18ga)
As Sumitomo connectors aren't widely available, a better source for this connector is Aliexpress where is is often sold as a complete connector kit.
Alternatively, there's a common Nissan/Subaru O2 sensor connector, with flying leads furnished, that is a perfect fit[3].
Pinout
Issues
The pump has a flow sensor, so it will not run empty/dry. Even when primed, the pump takes a moment to spool up.
Annoyingly, the bearing is integral to the impeller, so if you have a noisy pump there is no way to replace just the worn part.