Pinpoint Test AJ: DTC P0AE5:00
High-Voltage Traction Battery
Pinpoint Test AJ: DTC P0AE5:00
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 the BECM senses the precharge contactor fails to close the stop safely hazard (red triangle) warning indicator is illuminated and the vehicle will shut down and/or not start.
- P0AE5:00 (Hybrid Battery Precharge Contactor Control Circuit Range/Performance: No Sub Type Information) - If the BECM signal to close the contactor fails, this DTC will be set. Reports as a continuous memory (historical) DTC only.
This pinpoint test is intended to diagnose the following:
- BECM
- High-voltage Bussed Electrical Center (BEC)
- High Voltage Traction Battery (HVTB)
PINPOINT TEST AJ: DTC P0AE5:00
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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AJ1 CHECK CONTACTOR RESISTOR
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.
- With the service disconnect plug removed, measure the resistance of the precharge resistor in the BEC.
- Is the resistance between 6-10 ohms?
Yes
GO to AJ2.
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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AJ2 MEASURE CONTACTOR COIL RESISTANCE
- Disconnect: High-voltage BEC C4236D.
- With the service disconnect plug removed, measure the resistance between high-voltage BEC C4236D pin 4 and pin 5, component side.
- Is the resistance between 5-50 ohms?
Yes
GO to AJ3.
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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AJ3 CHECK FOR OPEN IN CIRCUIT
- Measure the resistance between high-voltage BEC C4236D, harness side and BECM C4237B, harness side as follows:
- Are the resistances less than 5 ohms?
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
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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