P1A04

P1A04-INVERTER ELECTRONIC COOLANT PUMP SUPPLY VOLTAGE - HEV





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 the TPIM coolant pump has a supply voltage of greater than 20.5 Volts or less than 7 Volts.





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

NOTE: TPIM coolant pump will perform a stalled pump clear routine when either the pumps stalls or comes in contact with an obstruction in the cooling system.

1. ACTIVE DTCS

NOTE: If the are charging system DTCs diagnose those first.

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. CHECK THE TIPM FUSED B+ VOLTAGE




1. Turn ignition off
2. Disconnect the TPIM cooling pump harness connector.
3. Turn ignition on
4. Measure the voltage of the (N311) Fused B+ circuit in the TIPM cooling pump harness connector.

Is the voltage less than 20.5 Volts and greater than 7 Volts?

Yes

- Go To 3

No

- Repair the (N311) Fused B+ circuit for an open circuit, high resistance or short to voltage.
- Perform TPIM VERIFICATION TEST.

3. (Z982) TPIM COOLING PUMP GROUND CIRCUIT OPEN




1. Measure the resistance of the (Z982) TPIM cooling pump ground circuit.

Is the resistance below 5.0 Ohms?

Yes

- Replace the TPIM coolant pump. Perform TPIM VERIFICATION TEST.

No

- Repair the open in the (Z982) TPIM cooling pump ground circuit.
- Replace the TPIM coolant pump. Perform TPIM VERIFICATION TEST.