Pinpoint Test F: DTCs P0A8B:64
High-Voltage Traction Battery
Pinpoint Test F: DTCs P0A8B:64
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 Electronically Controlled Continuously Variable Transmission (eCVT) engages the generator (also in the eCVT), which charges the High Voltage Traction Battery (HVTB) and supplies high-voltage to the DC to DC Converter Control Module (DC/DC). The DC/DC charges the low-voltage battery which is used to power the PCM and low voltage components. The DC/DC steps the high voltage down to 12 volts (operating range of 13.3-14.7 volts). This DTC may indicate a low state-of-charge in the 12-volt battery or a Battery Energy Control Module (BECM) fault. If the 12-volt battery has recently had the terminals disconnected/cleaned or if a new 12-volt battery has been recently installed, this DTC will also be set. When a fault is present, the system will attempt to continue normal operation. There is no warning indicator for this fault.
- DTC P0A8B:64 (14 Volt Power Module System Voltage: Signal Plausibility) - Fault sets when voltage less than 2.5 volts or greater than 25 volts on the BECM input circuit is detected.
This pinpoint test is intended to diagnose the following:
- 12-volt battery
- Circuitry
- BECM
PINPOINT TEST F: DTC P0A8B:64
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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F1 CHECK FOR 12-VOLT INPUT
- Ignition OFF.
- Disconnect: BECM C4237A.
- Ignition ON.
- Measure the voltage between BECM C4237A-47, circuit SBB17 (RD), harness side and ground; and between BECM C4237A-48, circuit SBB17 (RD), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to F2.
No
VERIFY the Smart Junction Box (SJB) fuse 17 (10A) is OK. If the fuse is OK, REPAIR the circuit. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Diagrams By Number
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F2 CHECK FOR GROUND CIRCUIT
- Ignition OFF.
- Measure the resistance between BECM C4237A-49, circuit GD126 (BK/WH), harness side and ground; and between BECM C4237A-50, circuit GD126 (BK/WH), harness side and ground.
- Are the resistances less than 5 ohms?
Yes
GO to F3.
No
REPAIR the circuit(s) as necessary. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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F3 CHECK FOR CORRECT BECM OPERATION
- 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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