Pinpoint Test L: U300A:01

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 Wiring Diagrams Power Distribution for schematic and connector information.

Normal Operation and Fault Conditions

REFER to: Steering Wheel and Column Electrical Components - System Operation and Component Description .

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
BCM U300A:01	Ignition Switch: General Electrical Failure	Sets when the BCM detects an invalid combination from the ignition switch input circuits, such as a voltage signal only from the ON-designated circuit, a voltage signal only from the START-designated circuit or a voltage signal from ACC and START-designated circuits at the same time.

Possible Sources

Wiring, terminals or connectors
Ignition switch
BCM

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

L1 CHECK FOR IGNITION SWITCH CIRCUITS FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect BCM C2280B.

Disconnect BCM C2280A.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2280B-50	Courtesy of FORD MOTOR COMPANY	Ground
C2280B-37	Courtesy of FORD MOTOR COMPANY	Ground
C2280A-14	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit in question.

GO to L2

L2 CHECK THE IGNITION SWITCH CIRCUITS FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2280B-50	Courtesy of FORD MOTOR COMPANY	C250-6
C2280B-37	Courtesy of FORD MOTOR COMPANY	C250-2
C2280A-14	Courtesy of FORD MOTOR COMPANY	C250-1

Are the resistances less than 3 ohms?

Yes	INSTALL a new ignition switch. REFER to: Ignition Switch . REFER to: Ignition Switch - Vehicles With: Keyless Vehicle System . . TEST the system for normal operation. IF the concern is still present, GO to L3

No	REPAIR the circuit in question.

L3 CHECK FOR CORRECT BCM (BODY CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all BCM connectors.

Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

Reconnect the BCM connectors and all other previously disconnected connectors. Make sure they seat and latch correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable service articles: TSB, GSB, SSM, or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, INSTALL a new BCM REFER to: Body Control Module (BCM) .

No	The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.