Pinpoint Test AH: DTC P0AE0:00

High-Voltage Traction Battery

Pinpoint Test AH: DTC P0AE0:00

Refer to Wiring Diagram Set 12 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Charging System for schematic and connector information. 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 sends a signal to the contactor to close, which will supply high-voltage power to the vehicle. If an overcurrent condition is sensed by the BECM, the stop safely hazard (red triangle) warning indicator is illuminated and the vehicle will shut down and/or not start.

- P0AE0:00 (Hybrid Battery Negative Contactor Control Circuit High: No Sub Type Information) - If the BECM detects overcurrent on the contactor control circuit for 16 milliseconds or more, this DTC will be set. Reports as a continuous memory (historical) DTC only.

This pinpoint test is intended to diagnose the following:
- Circuitry
- High Voltage Traction Battery (HVTB)
- BECM
- High-Voltage Bussed Electrical Center (BEC)


PINPOINT TEST AH: DTC P0AE0:00

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.

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AH1 CHECK FOR SHORT IN CIRCUIT

- Ignition OFF.
- Disconnect: BECM C4237B.
- Ignition ON.
- Measure the voltage between BECM C4237B-55, circuit J1-A55, harness side and ground; and between BECM C4237B-56, circuit J1-A56, harness side and ground.




- Is any voltage present?

Yes
GO to AH2.

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

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AH2 MEASURE CONTACTOR COIL RESISTANCE

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 system. Refer to High-Voltage Traction Battery Systems Depowering High-Voltage Traction Battery Systems Depowering.
- Remove the high-voltage BEC cover. Refer to the exploded view in Battery Pack Sensor Module (BPSM) Service and Repair.
- Disconnect: High-voltage BEC C4236D.
- With the service disconnect plug removed, measure the resistance between high-voltage BEC C4236 pin 7 and pin 8, component side.
- Is the resistance between 5-50 ohms?

Yes
GO to AH3.

No
INSTALL a new high-voltage BEC. REFER to High-Voltage Bussed Electrical Center Service and Repair. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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AH3 CHECK FOR CORRECT BECM OPERATION

- Ignition OFF.
- Check the BECM harness and component side connectors for:

- corrosion.
- pushed-out/bent pins.
- Connect the BECM and make sure the connectors seat correctly.
- Connect: High-voltage BEC C4236D.
- Install the high-voltage BEC cover. Refer to the exploded view in Battery Pack Sensor Module (BPSM) Service and Repair.
- Connect: Service Disconnect Plug.
- Operate the system and determine if the concern is still present.
- Is the concern still present?

Yes
INSTALL a new BECM. REFER to Battery Energy Control Module (BECM) Service and Repair. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

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