P1A09
P1A09-INVERTER ELECTRIC COOLANT PUMP- LIMP MODE ACTIVE - 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 is no longer reporting on the Local Interface Network (LIN) bus.
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 conditions that set this DTC are no longer present.
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test
2. TPIM COOLING PUMP (N311) FUSED B+ CIRCUIT OPEN
1. Turn the ignition off
2. Disconnect the TPIM Cooling Pump harness connector
3. Ignition on, engine not running.
4. Using a 12-volt test light probe both the (N311) Fused B+ circuit and (F1) Fused Ignition Switch Output circuit (OFF-RUN-START)
NOTE: The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 3
No
- Repair the excessive resistance or short to ground in the (N311) Fused B+ circuit and (F1) Fused Ignition Switch Output circuit (OFF-RUN-START).
- Perform TPIM VERIFICATION TEST.
3. EXCESSIVE RESISTANCE OR OPEN (Z982) TPIM COOLANT PUMP GROUND CIRCUIT
1. Turn the ignition off
2. Measure the resistance of the (Z982) TPIM Coolant Pump ground circuit from the TPIM Coolant Pump harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Go To 4
No
- Repair the excessive resistance or open in the (Z982) TPIM Coolant Pump ground circuit.
- Perform TPIM VERIFICATION TEST.
4. LIN BUS (D500) CIRCUIT OPEN
1. Disconnect the C4 PCM harness connector
2. Disconnect the auxiliary heater pump harness connector
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis.
3. Measure the resistance of the (D500) TPIM Coolant Pump LIN bus signal circuit from the TPIM Coolant Pump harness connector to the appropriate terminal of PCM Pinout Box 8815.
Is the resistance below 5.0 Ohms?
Yes
- Go To 5
No
- Repair the excessive resistance or open in the (Z982) TPIM coolant pump ground circuit.
- Perform TPIM VERIFICATION TEST.
5. LIN BUS (D500) CIRCUIT SHORT TO GROUND
1. Measure the resistance of the (D500) TPIM coolant pump LIN bus signal circuit from the TPIM Coolant Pump harness connector to the appropriate terminal of PCM Pinout Box 8815.
Is the resistance below 100 Ohms?
Yes
- Go To 6
No
- Repair the short to ground on the LIN bus (D500) circuit.
- Perform TPIM VERIFICATION TEST.
6. LIN BUS (D500) CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage of the (D500) TPIM coolant pump LIN bus signal circuit from the TPIM coolant pump harness connector.
Is there any voltage present?
Yes
- Repair the short to voltage in the LIN bus (D500) circuit.
- Perform TPIM VERIFICATION TEST.
No
- Replace the TPIM Coolant Pump
- Perform TPIM VERIFICATION TEST.