Pinpoint Test N: DTC B1143

High-Voltage Traction Battery

Pinpoint Tests

Pinpoint Test N: DTC B1143

Refer to Wiring Diagram Set 12 (Escape/Mariner, Escape Hybrid/Mariner Hybrid), Charging System for schematic and connector information. Diagrams By Number

Normal Operation

When the key is turned to the ON position, the PCM sends a request to the Battery Control Module (BCM) over the Controller Area Network (CAN) communication link to close the High Voltage Traction Battery (HVTB) contactors.

- DTC B1143 (Excessive Battery Contactor Close Requests) - If the PCM sends 100 requests in 4 minutes (or less) to close the HVTB contactors, the BCM will set this DTC.

This pinpoint test is intended to diagnose the following:
- Rapid key cycling/excessive contactor close requests
- CAN communication link
- PCM
- BCM
- Real-time clock




PINPOINT TEST N: DTC B1143

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N1 CHECK FOR RAPID KEY CYCLING



NOTE: On-demand DTCs may not yield the DTC B1143. Continuous memory DTCs must be retrieved to verify that DTC B1143 is not present.

- Using the scan tool, clear the BCM DTCs.
- Ignition OFF.
- Ignition ON.
- Wait 5 minutes.
- Enter the following diagnostic mode on the scan tool: Self Test - BCM.
- Is DTC B1143 still present?

Yes
GO to N2.

No
RETURN the vehicle to the customer. The concern may have been caused by rapid key cycling.

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N2 CHECK THE CAN COMMUNICATION LINK



- Check the recorded BCM DTCs from the continuous and on-demand self tests.
- Are any BCM communication link DTCs (Uxxx) present?

Yes
REFER to Information Bus to continue diagnosis of the communication network.

No
GO to N3.

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N3 CHECK FOR CORRECT PCM OPERATION



- Disconnect PCM electrical connectors C175B, C175E and C175T.
- Check for:
- corrosion.
- pushed-out pins.
- Connect PCM electrical connectors C175B, C175E and C175T and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new PCM. REFER to Computers and Control Systems. CLEAR the BCM DTCs. CYCLE the ignition switch to OFF, then ON and leave ON for 5 minutes. TEST the system for normal operation. If vehicle does not start, GO to N4.

No
GO to N4.

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N4 CHECK FOR CORRECT BCM OPERATION



NOTE: This pinpoint test step only addresses the 40-pin connectors 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 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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