Pinpoint Test E: DTCs P0A8B, P0A8D or P0A8E
High-Voltage Traction Battery
Pinpoint Tests
Pinpoint Test E: DTCs P0A8B, P0A8D or P0A8E
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 engine must have started at least once after the key was cycled to ON), the planetary gear set in 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/DC converter. The DC/DC converter steps the high voltage down to 12 volts (operating range of 13.35-16 volts). The DC/DC converter charges the low-voltage battery which is used to power the PCM and low-voltage components.
- DTC P0A8B (14-Volt Power Module System Voltage) - Voltage less than 2.5 volts or greater than 25 volts on input circuit SBB05 (GY/RD) indicates an internal Battery Control Module (BCM) fault will cause the BCM to set this DTC. Also if the 12-volt battery has recently had the terminals disconnected/cleaned or if a new 12-volt battery has been recently installed, the BCM may set this DTC.
- DTC P0A8D (14-Volt Power Module System Voltage Low) - Voltage less than 10 volts on input circuit SBB05 (GY/RD) for 5 seconds continuously, the 12-volt battery recently having the terminals disconnected/cleaned or if a new 12-volt battery having been recently installed may cause the BCM to set this DTC.
- DTC P0A8E (14-Volt Power Module System Voltage High) - Voltage greater than 16 volts on input circuit SBB05 (GY/RD) for 5 seconds continuously, the 12-volt battery recently having the terminals disconnected/cleaned or if any external jump start procedure having been carried out recently may cause the BCM to set this DTC.
This pinpoint test is intended to diagnose the following:
- 12-volt battery
- HVTB
PINPOINT TEST E: DTC P0A8B, P0A8D OR P0A8E
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E1 CHECK THE HISTORY OF THE VEHICLE
- Verify if the low-voltage battery has recently had the terminals disconnected/cleaned or if a new low-voltage battery has been recently installed. If so, DTCs P0A8B, P0A8D and P0A8E may have been set.
- Has the low-voltage battery recently had the terminals disconnected/cleaned or has a new low-voltage battery recently been installed?
Yes
CLEAR the DTCs. REPEAT the self-test. If the self-test passes, RETURN the vehicle to the customer until the concern can be verified.
No
GO to E2.
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E2 VERIFY THE INTEGRITY OF THE LOW-VOLTAGE BATTERY
- Refer to Battery and carry out Pinpoint Test A: Battery Condition test to determine if the battery can hold a charge and is OK for use. Pinpoint Tests
- Does the battery pass the condition test?
Yes
GO to E3.
No
INSTALL a new 12-volt battery. REFER to Battery. TEST the system for normal operation.
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E3 CHECK THE BCM DTCs
- Using the scan tool, clear the BCM DTCs.
- Cycle the ignition OFF then ON.
- Enter the following diagnostic mode on the scan tool: Self Test - BCM.
- Are the following DTCs retrieved: P0A8B, P0A8D or P0A8E?
Yes
GO to E4.
No
REFER to Computers and Control Systems Information to continue diagnosis.
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E4 CHECK FOR 12-VOLT INPUT ON CIRCUIT SBB05 (GY/RD)
- Ignition OFF.
- Disconnect: BCM C4227A.
- Ignition ON.
- Check the voltage between BCM C4227A-10, circuit SBB05 (GY/RD), harness side and ground.
- Check the voltage between BCM C4227A-11, circuit SBB05 (GY/RD), harness side and ground.
- Are the voltages greater than 10 volts?
Yes
GO to E5.
No
REPAIR circuit SBB05 (GY/RD). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal condition.
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E5 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.
- Check BCM electrical connector C4227A for:
- corrosion.
- pushed-out pins.
- Connect BCM electrical connector 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 Removal and Replacement. 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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