Pinpoint Test A: An Auxiliary Switch Controlled Component Is Inoperative

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 Customer Access for schematic and connector information.
Normal Operation and Fault Conditions

REFER to: Auxiliary Switches .

Possible Sources
- Wiring, terminals or connectors
- Fuses
- Upfitter (auxiliary) switch assembly
- BJB (BCMC)

A1 CHECK THE AUXILIARY SYSTEM
- Ignition ON.
- Operate all the upfitter accessories.
Are all the upfitter accessories inoperative?

Yes GO to Pinpoint Test B

No GO to A2

A2 CHECK THE VOLTAGE AT THE UPFITTER RELAY FUSE

NOTE: The Upfitter Relays are internal to the BJB (BCMC) and are non -serviceable.

Ignition ON.

Place the upfitter switch in question to the ON position.

NOTE: When measuring the voltage at the upfitter relay fuse make sure the fuse is seated enough to make contact with the BJB (BCMC) terminal and the positive lead probe from the meter. A fuse jumper wire may be used to aid in this measurement.

For the upfitter relay fuse in question, measure:

Positive Lead	Measurement / Action	Negative Lead
(Upfitter Relay 1 Fuse, FS60, 15A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 2 Fuse, FS61, 15A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 3 Fuse, FS62, 10A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 4 Fuse, FS63, 10A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 5 Fuse, FS305, 5A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 6 Fuse, FS306, 5A)	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes	REPAIR the Upfitter relay output to customer installed equipment circuit in question.

GO to A3

A3 CHECK THE CONTROL VOLTAGE TO THE UPFITTER RELAY

NOTE: The Upfitter Relays are internal to the BJB (BCMC) and are non serviceable.

Ignition OFF.

Disconnect Upfitter switch C9120.

NOTE: If the jumper wire fuse fails during this step, refer to the OEM WIRING DIAGRAMS to identify the possible causes for a short to ground.

For the auxiliary switch in question, connect:

Positive Lead	Measurement / Action	Negative Lead
C9120-2 (AUX 1)	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY
C9120-3 (AUX 2)	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY
C9120-4 (AUX 3)	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY
C9120-10 (AUX 4)	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY
C9120-8 (AUX 5)	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY
C9120-7 (AUX 6)	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY

For the auxiliary switch in question, measure:

Positive Lead	Measurement / Action	Negative Lead
(Upfitter Relay 1 Fuse, FS60, 15A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 2 Fuse, FS61, 15A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 3 Fuse, FS62, 10A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 4 Fuse, FS63, 10A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 5 Fuse, FS305, 5A)	Courtesy of FORD MOTOR COMPANY	Ground
(Upfitter Relay 6 Fuse, FS306, 5A)	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes	REMOVE the fused jumper wire. INSTALL a new auxiliary switch assembly. REFER to: Auxiliary Switches .

No	REMOVE the fused jumper wire. GO to A4

A4 CHECK THE CONTROL VOLTAGE TO THE UPFITTER RELAY

Disconnect Upfitter switch C9120.

Disconnect For the circuit in question, BJB (BCMC) C1035C or BJB (BCMC) C1035B.

For the auxiliary switch in question, measure:

Positive Lead	Measurement / Action	Negative Lead
C9120-2 (AUX 1)	Courtesy of FORD MOTOR COMPANY	C1035B-42 (AUX 1)
C9120-3 (AUX 2)	Courtesy of FORD MOTOR COMPANY	C1035B-40 (AUX 2)
C9120-4 (AUX 3)	Courtesy of FORD MOTOR COMPANY	C1035B-35 (AUX 3)
C9120-10 (AUX 4)	Courtesy of FORD MOTOR COMPANY	C1035B-37 (AUX 4)
C9120-8 (AUX 5)	Courtesy of FORD MOTOR COMPANY	C1035C-41 (AUX 5)
C9120-7 (AUX 6)	Courtesy of FORD MOTOR COMPANY	C1035C-40 (AUX 6)

Is the resistance less than 3 ohms?

Yes

GO to A5

No	REPAIR the circuit in question.

A5 CHECK FOR CORRECT BCMC (BODY CONTROL MODULE C) OPERATION

Ignition OFF.

Disconnect and inspect all BCMC 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 BCMC 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 BCMC. REFER to: Body Control Module C (BCMC) .

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. CLEAR the Diagnostic Trouble Codes (DTCs).