P0AA4

High-Voltage Traction Battery

Pinpoint Test I: DTC P0AA4:00 or P0AA5:00

Refer to Wiring Diagram Set 12, Charging System for schematic and connector information. [1][2]Diagrams By Number

Normal Operation

When the ignition is turned on, the Battery Energy Control Module (BECM) makes various vehicle checks. If these checks are normal, the BECM (Battery Energy Control Module) sends a signal to the contactor to close which will supply power to the vehicle. The stop safely hazard (red triangle) warning indicator will illuminate for both DTCs. For DTC P0AA4:00, the vehicle will not start at the next ignition cycle. For P0AA5:00, the vehicle is shut down.

- DTC P0AA4:00 (Hybrid Battery Negative Contactor Circuit Stuck Closed: No Sub Type Information)- If the contactor is stuck closed, this DTC will be set. Reports as a continuous memory (historical) DTC only.

- DTC P0AA5:00 (Hybrid Battery Negative Contactor Circuit Stuck Open: No Sub Type Information)- If the contactor is stuck open for 2 seconds, this DTC will be set.

This pinpoint test is intended to diagnose the following:

- BECM (Battery Energy Control Module)

- High-voltage Bussed Electrical Center (BEC)

- High Voltage Traction Battery (HVTB)

PINPOINT TEST I : DTC P0AA4:00 OR P0AA5:00

WARNING: To prevent the risk of high-voltage shock, always follow precisely all warnings and service instructions, including instructions to depower the system. The high-voltage hybrid system utilizes approximately 300 volts DC, provided through high-voltage cables to its components and modules. The high-voltage cables and wiring are identified by orange harness tape or orange wire covering. All high-voltage components are marked with high-voltage warning labels with a high-voltage symbol. Failure to follow these instructions may result in serious personal injury or death.

NOTICE: Use the correct probe adapter(s) from the Flex Probe Kit when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.

I1 MEASURE VOLTAGE AT THE BECM (Battery Energy Control Module) CONNECTOR

- Ignition ON.

- Measure voltage between BECM (Battery Energy Control Module) C4237B-55, circuit J1-A55 harness side and ground, by back-probing the BECM (Battery Energy Control Module) connector.





Is the voltage between 5-6 volts?

Yes
GO to I2.

No
INSTALL a new BECM (Battery Energy Control Module). REFER to Battery Energy Control Module (BECM) . CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

I2 MEASURE VOLTAGE AT THE BECM (Battery Energy Control Module) CONNECTOR

- Ignition ON.

- Measure voltage between BECM (Battery Energy Control Module) C4237B-55, circuit J1-A55, harness side, and BECM (Battery Energy Control Module) C4237B-56, circuit J1-A56, harness side, by back-probing the BECM (Battery Energy Control Module) connector.





Is the voltage between 5-6 volts?

Yes
GO to I3.

No
INSTALL a new BECM (Battery Energy Control Module). REFER to Battery Energy Control Module (BECM) . CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

I3 CHECK CONTACTOR WIRING

WARNING: Never install the service disconnect plug with the high-voltage bussed electrical center (BEC) cover removed. Always install the cover prior to connecting the service disconnect plug. The high-voltage BEC cover prevents inadvertent contact with the high voltage which is present at several points under the cover. Failure to follow these instructions may result in serious personal injury or death.

- Ignition OFF.

- Depower the HVTB (High Voltage Traction Battery) system. Refer to High-Voltage Traction Battery Systems Depowering .

- Disconnect the 12-volt battery

- Remove the high-voltage BEC (Bussed Electrical Center) cover. Refer to the exploded view in Battery Pack Sensor Module (BPSM) .

- Disconnect: BECM (Battery Energy Control Module) C4237B.

- Disconnect: High-voltage BEC (Bussed Electrical Center) C4236D.

- Measure the resistance between high-voltage BEC (Bussed Electrical Center) C4236D-7, circuit J1-A55, harness side and BECM (Battery Energy Control Module) C4237B-55, circuit J1-A55, harness side; and between high-voltage BEC (Bussed Electrical Center) C4236D-8, circuit J1-A56, harness side and BECM (Battery Energy Control Module) C4237B-56, circuit J1-A56, harness side.





Are the resistances less than 5 ohms?

Yes
INSTALL a new high-voltage BEC (Bussed Electrical Center). REFER to High-Voltage Bussed Electrical Center . CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
INSTALL a new HVTB (High Voltage Traction Battery) (includes HVTB (High Voltage Traction Battery) system wire harness). REFER to High-Voltage Traction Battery . CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.