Pinpoint Test C: DTC P0A7E
High-Voltage Traction Battery
Pinpoint Tests
Pinpoint Test C: DTC P0A7E
Refer to Wiring Diagram Set 12 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), Charging System for schematic and connector information. Diagrams By Number
Normal Operation
With the ignition switch in the ON position and the engine ON or OFF, the vehicle climate control system maintains the High Voltage Traction Battery (HVTB) temperature in a specific range. The HVTB has 2 internal fans that circulate climate controlled air within the HVTB so a specific temperature range is maintained. A battery compartment thermistor is hardwired to the HVTB for the battery compartment temperature input. The HVTB also monitors the battery compartment blend door actuator in order to determine the direction the HVTB operates the battery blend door motor. The battery blend door controls whether the air flowing into the battery compartment is fresh air or recirculated air. A battery thermal expansion solenoid valve also controls the refrigerant pressure, thereby controlling the incoming air temperature. The ideal HVTB temperature is 25°C (77°F) with a desired range of 20°C (68°F) to 30°C (86°F).
- DTC P0A7E (Hybrid Battery Pack Over Temperature) - The HVTB temperature window is -40°C (-104°F) to 55°C (131°F). If the HVTB temperature exceeds 55°C (131°F) and the vehicle is driven aggressively, the Battery Control Module - High Voltage Traction Battery (BCM-HVTB) may set this DTC and if the HVTB temperature exceeds 57°C (135°F), the BCM-HVTB may shut the vehicle down.
This pinpoint test is intended to diagnose the following:
- Vehicle climate control system
- HVTB internal fans
- HVTB
PINPOINT TEST C: DTC P0A7E
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C1 VERIFY THE VEHICLE CLIMATE CONTROL SYSTEM IS OPERATING CORRECTLY
- Start the engine.
- Turn the A/C system to MAX A/C.
- NOTE: Allow the climate control system to reach normal operating temperature (stabilized).
- With the engine running at 2,000 rpm, place a thermometer in the center climate control outlet vents and monitor the outlet temperature.
- Is the outlet temperature between 0°C and 9°C (32°F and 48°F)?
Yes
GO to C2.
No
REFER to Climate Control System - General Information and Diagnostics - Hybrid Testing and Inspection to continue diagnosis of the vehicle climate control system.
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C2 VERIFY THE HVTB INTERNAL FANS ARE OPERATIONAL
NOTE: Use a stethoscope or equivalent listening device to probe the HVTB area while the self-test is proceeding.
- Enter the following diagnostic mode on the scan tool: Self Test - BCM-HVTB.
- NOTE: The cooling fans may cycle on or off with the ignition switch in the ON position and the engine ON or OFF.
- With the ignition switch in the ON position and the engine ON or OFF (the engine must have run at least once after the key was cycled to ON), verify the HVTB internal fans are operating correctly.
- Are the HVTB internal fans operating correctly?
Yes
GO to C3.
No
GO to Pinpoint Test D. Pinpoint Test D: DTCs P0A81 Or P0A96
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C3 CHECK THE HVTB TEMPERATURE
- Enter the following diagnostic mode on the scan tool: DataLogger - BCM-HVTB.
- With the engine running, monitor the BCM-HVTB AVG_TEMP PID.
- Is the BCM-HVTB AVG_TEMP PID less than 55°C (131°F)?
Yes
GO to C4.
No
REFER to Climate Control System - General Information and Diagnostics - Hybrid Testing and Inspection to continue diagnosis of the vehicle climate control system.
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C4 CHECK FOR CORRECT BCM-HVTB OPERATION
NOTE: This pinpoint test step only addresses the 40-pin connector for the BCM-HVTB. It is not necessary to disconnect the high-voltage connectors when following this pinpoint test step procedure.
- Disconnect BCM-HVTB electrical connector C4227A.
- Check for:
- corrosion.
- pushed-out pins.
- Connect BCM-HVTB connectors C4227A and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new HVTB. REFER to High-Voltage Traction Battery Service and Repair. 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.
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