Pinpoint Test C: B11D9:09

WARNING: This page is about a different car, the 2021 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.

Refer to CHARGING SYSTEM for schematic and connector information.

Normal Operation and Fault Conditions

The BCM monitors both the main battery and auxiliary battery(ies). The main battery has a BMS and the auxiliary battery(ies) has a battery current sensor. The BMS for the main battery communicates on a dedicated LIN to the BCM. The battery current sensor for the auxiliary battery(ies) uses a PWM circuit which is wired to the BCM.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
BCM B11D9:09	Vehicle Battery: Component Failures	Sets in the BCM when the BMS senses a failed battery due to one of the following conditions. Failure of the 12 volt main engine compartment battery Disconnected 12 volt main engine compartment battery Failure of the auxiliary battery(ies) set after 10 engine cranks Open auxiliary battery(ies) fuse (in the high current BJB) Open auxiliary battery(ies) fuse (attached to the auxiliary battery(ies) post) Disconnected auxiliary battery(ies), set after 10 engine cranks

Possible Sources

Auxiliary battery(ies)
Auxiliary battery(ies) fuses
Main engine compartment battery
Main engine compartment battery and auxiliary battery(ies) connections

Visual Inspection and Pre-checks

Verify the auxiliary battery(ies) fuses

C1 INSPECT ALL BATTERY CONNECTIONS
- Ignition OFF.
- Inspect the 12 volt main engine compartment battery connections.
- NOTE: Vehicles equipped with two auxiliary batteries, the batteries are two 12 volt batteries connected in series creating a 24 volt battery supply.
  
  Inspect the auxiliary battery(ies) connections.
Are all battery cable connections securely fasten to the main and auxiliary battery(ies)?

Yes GO to C2

No Secure the loose battery cable(s) connections to the battery.

C2 CHECK THE AUXILIARY BATTERY(IES) FUSE

Verify that the auxiliary battery(ies) fuses are ok.
- auxiliary battery(ies) fuse located in the high current BJB.
- auxiliary battery(ies) fuse located on the auxiliary battery(ies) positive post.

Are the auxiliary battery(ies) fuses ok?

Yes

GO to C3

No	Verify that the battery cable is not shorted, If OK, Install a new auxiliary battery(ies) fuse(s). If shorted, REPAIR or REPLACE the auxiliary battery(ies) cable as needed.

C3 VERIFY THE BATTERIES CONDITION

Verify that the main battery and auxiliary battery(ies) condition. For the main battery GO to Pinpoint Test A For the auxiliary battery(ies), GO to Pinpoint Test B

Does the main engine compartment battery and auxiliary battery(ies) pass the condition test?

Yes	RETURN the battery to service. CLEAR the DTC and RETEST the system.

No	If the analyzer reads REPLACE BATTERY or REPLACE-BAD CELL or does not pass the battery condition test, INSTALL a new battery for the one in question. REFER to: Battery . or REFER to: Auxiliary Battery .