Pinpoint Test AJ : The GFM2 (Generic Function Module 2) Does Not Respond To The Diagnostic Scan Tool

WARNING: This page is about a different car, the 2018 Ford F-550 Super Duty, 2018 Ford F-450 Super Duty, 2018 Ford F-350 Super Duty, and 2018 Ford F-250 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.

AJ1 CHECK THE GFM2 (GENERIC FUNCTION MODULE 2) VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

Ignition OFF.

Disconnect: GFM2 C290C

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C290C-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the voltage greater than 11 volts?

Yes

GO to AJ2

No	VERIFY BJB fuse 91 (10A) is OK. If OK, REPAIR the circuit. If not OK, REFER to the OEM Wiring Diagrams to identify the possible causes of the circuit short.

AJ2 CHECK THE GFM2 (GENERIC FUNCTION MODULE 2) GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C290C-4	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes

GO to AJ3

No	REPAIR the circuit.

AJ3 CHECK THE HS-CAN1 (HIGH SPEED-CONTROLLER AREA NETWORK 1) CIRCUITS BETWEEN THE GFM2 (GENERIC FUNCTION MODULE 2) AND THE DLC (DATA LINK CONNECTOR) FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C290C-6	Courtesy of FORD MOTOR COMPANY	C251-6
C290C-7	Courtesy of FORD MOTOR COMPANY	C251-14

Are the resistances less than 3 ohms?

Yes

GO to AJ4

No	REPAIR the circuit in question.

AJ4 CHECK FOR CORRECT GFM2 (GENERIC FUNCTION MODULE 2) OPERATION

Ignition OFF.

Disconnect and inspect the GFM2 connectors and related in-line 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 GFM2 connectors and related in-line 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 Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new GFM2. Refer to: Generic Function Module 2 (GFM2) .

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.