Pinpoint Test D: DTCs P0A81 or P0A96
High-Voltage Traction Battery
Pinpoint Tests
Pinpoint Test D: DTCs P0A81 or P0A96
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), 2 internal fans in the High Voltage Traction Battery (HVTB) circulate air to maintain a specific temperature range. A failure of the cooling fan(s) or their associated circuits causes one (or both) of the DTCs to be set.
- P0A81 (Hybrid Battery Pack Cooling Fan 1 Control Circuit) - An open in Battery Junction Box (BJB) fuse 15 (50A), an HVTB cooling fan 1 fault, circuit SBB15 (WH/RD) feedback status not matching Battery Control Module (BCM) commands or an open or high resistance on HVTB ground circuit GD149 (BK/GY) will cause the BCM to set this DTC.
- P0A96 (Hybrid Battery Pack Cooling Fan 2 Control Circuit) - An open in BJB fuse 15 (50A), an HVTB cooling fan 2 fault, circuit SBB15 (WH/RD) feedback status not matching BCM commands or an open or high resistance on HVTB ground circuit GD149 (BK/GY) will cause the BCM to set this DTC.
This pinpoint test is intended to diagnose the following:
- Fuse
- Circuitry
- Cooling fan 1 or 2 (part of HVTB)
- HVTB
PINPOINT TEST D: DTC P0A81 OR P0A96
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D1 CHECK CIRCUIT SBB15 (WH/RD) FOR VOLTAGE
- Ignition OFF.
- Disconnect: BCM C4227A.
- Measure the voltage between BCM C4227A pins, harness side and ground as follows:
- Is the voltage greater than 10 volts?
Yes
GO to D2.
No
VERIFY that the BJB fuse 15 (50A) is OK; if OK, REPAIR circuit SBB15 (WH/RD). If 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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D2 CHECK CIRCUIT GD149 (BK/GY) FOR AN OPEN
- Measure the resistance between BCM C4227A pins, harness side and ground as follows:
- Is the resistance less than 5 ohms?
Yes
GO to D3.
No
REPAIR circuit GD149 (BK/GY). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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D3 CHECK THE FAN CIRCUITS WHILE UNDER A LOAD
NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while making sure that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals or connectors and subsequent electrical faults.
- Connect: BCM C4227A.
- Carefully backprobe BCM C4227A-4 and BCM C4227A-35 as shown.
- Connect the scan tool.
- Ignition ON.
- NOTE: The HVTB cooling fans can only be commanded on by carrying out the BCM self-test. During the self-test, the fans will be commanded on by the BCM for only a few seconds. Be sure to monitor the multimeter for the entire duration of the self-test so that if a fault is present, it is not missed.
- Enter the following diagnostic mode on the scan tool: Self Test - BCM.
- While carrying out the BCM self-test, monitor the voltage displayed on the multimeter. If there is a resistance fault in the fan power circuits, the voltage value will decrease when the fans are commanded on.
- Is the voltage displayed on the multimeter greater than 10 volts throughout the ENTIRE self-test?
Yes
GO to D4.
No
REPAIR the HVTB cooling fan circuits. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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D4 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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