P1A03

P1A03-INVERTER ELECTRONIC COOLANT PUMP - COOLANT TO LOW - HEV





For a complete wiring diagram, consult the Wiring Information.

Theory of Operation

The Traction Power Inverter Module (TPIM) electronic's cooling system operates independent from the engine cooling system. The TPIM cooling system is designed to remove the heat generated by the inverters and the Accessory Power Module (APM). The system consists of a reservoir, electric pump, temperature sensor and cooler.

- When Monitored:
Continuously, with ignition on.

- Set Condition:
When the TPIM coolant pump reports to the Powertrain Control Module (PCM) that it's RPM is too high.





WARNING: On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure

1. ACTIVE DTCS
1. Ignition on, vehicle not in ready mode.
2. With the scan tool, check for active DTCs.

Is the DTC active?

Yes

- Go To 2

No

- The condition that caused this DTC to set is not present at this time. Attempt to operate the vehicle in the conditions stored in the Environmental Data. If the DTC will not set again, check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched and partially broken wires. Also inspect the related connectors for broken, bent, pushed out, spread, corroded or contaminated terminals.

2. TPIM COOLING SYSTEM LOW

WARNING: Never open the cooling system when the engine is hot. The system is under pressure. Failure to follow these instructions can result in personal injury including extreme burns, scalding, or fatal injury. Allow the engine to cool before opening the cooling system.

1. Check TPIM cooling system level.

Is the cooling system full?

Yes

- Go To 3

No

- Check for and repair any cooling system leaks. Fill cooling system to proper level. Cooling System Filling

3. CHECKING TPIM COOLING SYSTEM MIXTURE

NOTE: Use the TPIM cooling system coolant only. No other coolant should be used. The water used to dilute the coolant must be distilled or de-mineralized.

1. The TPIM coolant should be mixed 50/50.
2. Check TPIM cooling system fluid mixture.

Is the cooling system fluid mixed correctly?

Yes

- Go To 4

No

- Drain and refill cooling system with proper mixture. Service and Repair

4. TPIM COOLING SYSTEM PUMP
1. With the scan tool, actuate the TPIM cooling system pump.
2. Check TPIM cooling system pump operation.
3. Verify the cooling pump is operating and system has good coolant flow.

Is the TPIM cooling system pump operating normally?

Yes

- Go To 5

No

- Repair the TPIM cooling system pump as necessary. Perform TPIM VERIFICATION TEST. Pre-Diagnostic Troubleshooting Procedure

5. RADIATOR ELECTRIC COOLING FAN
1. With the scan tool, actuate the radiator electric cooling fan.
2. Check the radiator electric cooling fan operation.

NOTE: Check for any obstruction of the air flow through the TPIM cooler.

Is the radiator electric cooling fan operating normally with no air flow obstructions?

Yes

- If the TPIM cooling system is operating properly and the coolant temperature is not excessive, replace the TPIM coolant pump. Perform TPIM VERIFICATION TEST. Pre-Diagnostic Troubleshooting Procedure

No

- Repair the radiator electric cooling fan as necessary. Perform TPIM VERIFICATION TEST. Pre-Diagnostic Troubleshooting Procedure