Coolant Pump
See Figure 1. The coolant pump (7) is located in bottom of the motor housing and it circulates coolant through the system. The BCM controls coolant pump operation when the VSC (inside the ePTC) or OBC signals a coolant pump ON or OFF request. This only happens when certain conditions are met.
- BCM – Body Control Module
- PEU – Power Electronics Unit
- OBC – Onboard Charger
- VSC – Vehicle Supervisory Controller
Definitions
BCM Function
Start Coolant Pump – when following conditions are met:
- Pump requested - The VSC or OBC request cooling
- Vehicle upright - Tip over condition not detected
Stop Coolant Pump – when any of the following conditions are met:
- Both VSC and OBC request cooling off
- Vehicle tipped - Tip over condition is detected
- Critical pump fault detected
VSC Function
Start Coolant Pump – when following conditions are met:
- The propulsion system requests cooling when required
- The ePTC requests cooling through the VSC cooling signal
- Propulsion enabled - The pump shall not be enabled before propulsion is enabled
Stop Coolant Pump – when any of the following conditions are met:
- The ePTC coolant pump request may continue as long as required
OBC Function
Start Coolant Pump – when following conditions are met:
- The OBC requests cooling through the OBC cooling signal
- AC Charging - When AC charging is occurring, the OBC may request cooling
Stop Coolant Pump – when any of the following conditions are met:
- The OBC coolant pump request may continue as long as required
Quick Reference Pump Operation
Table 1. Pump Operation
STATUS | Coolant Pump | |
|---|---|---|
On | Off | |
AC Charging | X | |
Propulsion enabled | X | |
Vehicle upright | X | |
Vehicle tipped | X | |
Critical pump fault | X | |
Body Control Module (BCM) faulted | X | |
Onboard Charger (OBC) faulted | X | |
Open circuit to coolant pump | X | |
Pump will run after vehicle shutdown until 80 °C (176 °F) is reached or one minute, whichever occurs first. | ||
Coolant Flow
| 1. | See Figure 1. Radiator (3) to PEU (12). | |
| 2. | PEU (11) to coolant pump (6). | |
| 3. | Coolant pump (6) to motor (5). a. Coolant flows into the motor housing (5), through a network of passages, then to the outlet fitting hose (9) to PEU (11). | |
| 4. | Back up through the PEU (11) through a return channel, and into the radiator (3). |
| 1 | Coolant bottle |
| 2 | Radiator cap |
| 3 | Radiator |
| 4 | PEU to radiator hose |
| 5 | Motor |
| 6 | Bleed port screw |
| 7 | Coolant pump |
| 8 | PEU to coolant pump hose |
| 9 | Coolant pump to motor hose |
| 10 | Motor to PEU hose |
| 11 | Overflow tube |
| 12 | Power Electronics Unit (PEU) |
| 13 | Radiator to PEU hose |
Figure 1. Coolant Flow