Pinpoint Test D: DTC P0A81:00
High-Voltage Traction Battery
Pinpoint Test D: DTC P0A81:00
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
With the ignition in the ON position and the engine running or OFF (the engine must have started at least once after the ignition was cycled to ON), the external fan for the High Voltage Traction Battery (HVTB) circulates air to maintain a specific temperature range. The fan operation is controlled by the Battery Energy Control Module (BECM) based upon information received from thermistors located inside the HVTB. The stop safely hazard (red triangle) warning indicator or powertrain malfunction (wrench) warning indicator will illuminate when a fault condition is present.
- P0A81:00 (Hybrid Battery Pack Cooling Fan 1 Control Circuit Open: No Sub Type Information) - Fault sets if the BECM fan control output circuit indicates a fault for 5 seconds or more.
This pinpoint test is intended to diagnose the following:
- BECM
- Cooling fan
- HVTB
PINPOINT TEST D: DTC P0A81:00
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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D1 RETRIEVE ALL BECM DTCs
- Ignition OFF.
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Clear DTCs - BECM.
- Enter the following diagnostic mode on the scan tool: Self-Test - BECM.
- Is DTC P0A81:00 or P0A82:00 present?
Yes
GO to D2.
No
INSPECT inline C4013 and HVTB cooling fan C4232 for pushed-out or corroded pins and REPAIR as necessary. WIGGLE the wiring harness. REPEAT the self-test.
If DTC P0A81:00 or DTC P0A82:00 is retrieved, GO to D2.
If no DTCs are retrieved, The concern may have been caused by pushed-out or corroded pins. RETURN the vehicle to the customer.
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D2 CHECK FOR A SHORT TO GROUND IN THE FAN CONTROL CIRCUIT
- Ignition OFF.
- Disconnect: HVTB Cooling Fan C4232.
- Disconnect: BECM C4237A.
- Measure the resistance between BECM C4237A-14, circuit VYB18 (WH/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to D3.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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D3 CHECK HVTB COOLING FAN GROUND CIRCUIT
- Connect: BECM C4237A.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - BECM (fan still disconnected).
- Is DTC P0A82:00 present?
Yes
INSTALL a new fan. REFER to High-Voltage Traction Battery Cooling Fan Service and Repair. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to D4.
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D4 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.
- 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. 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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