Pinpoint Test C: DTC P0A7E - Hybrid Battery Pack Over Temperature
High-Voltage Traction Battery
Pinpoint Tests
Pinpoint Test C: DTC P0A7E - Hybrid Battery Pack Over Temperature
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 (BCM) may set this DTC and if the HVTB temperature exceeds 57°C (135°F), the BCM 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 - HYBRID BATTERY PACK OVER TEMPERATURE
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C1 VERIFY THE VEHICLE CLIMATE CONTROL SYSTEM IS OPERATING CORRECTLY
WARNING: Wear high-voltage insulated safety gloves and a face shield when working with high-voltage batteries or cables. The high-voltage insulated safety gloves should be of the appropriate safety and protection rating. Inspect the gloves before use and always wear them with the leather outer glove. Any hole in the rubber insulating glove is a potential entry point for high-voltage. Failure to follow these instructions may result in serious personal injury or death.
WARNING: Turn OFF the ignition switch for a minimum of 5 minutes before removing high-voltage cables. High-voltage cables and wiring are orange in color. The nominal high-voltage traction battery voltage (HVTB) is 330 V DC. Failure to follow these instructions may result in serious personal injury or death.
WARNING: Depower the high-voltage traction battery (HVTB) before carrying out any removal or installation procedures affecting the high-voltage battery system. Failure to follow this instruction may result in serious personal injury or death.
WARNING: When servicing the high-voltage system, establish a buffer zone per the specified procedure. Failure to follow this instruction may result in serious personal injury or death.
- 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 Heating and Air Conditioning to continue diagnosis of the vehicle climate control system.
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C2 VERIFY THE HVTB INTERNAL FANS ARE OPERATIONAL
- Enter the following diagnostic mode on the scan tool: BCM Self Test/Retrieve and Record On-Demand and Continuous Memory DTCs.
- NOTE: Use a stethoscope or equivalent listening device to probe the HVTB area while the self-test is proceeding.
- 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 And P0A96 - Hybrid Battery Pack Cooling Fans 1 And 2 Control Circuits
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C3 CHECK THE HVTB TEMPERATURE
- Start the engine.
- Connect the scan tool.
- Enter the following diagnostic mode on the scan tool: BCM DataLogger/PID.
- Enter the following diagnostic mode on the scan tool: BCM PID Average Temperature PID (AVG_TEMP).
- With the engine running, monitor the BCM (AVG_TEMP) PID.
- Is the BCM AVG_TEMP PID less than 55°C (131°F)?
Yes
GO to C4.
No
REFER to Heating and Air Conditioning to continue diagnosis of the vehicle climate control system.
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C4 CHECK FOR CORRECT BCM OPERATION
NOTE: This pinpoint test step only addresses the 40-pin connector for the BCM. It is not necessary to disconnect the high-voltage connectors when following this pinpoint test step procedure.
- Disconnect BCM electrical connector C4227a.
- Check for:
- corrosion.
- pushed-out pins.
- Connect BCM 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 High-Voltage Traction Battery. 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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