Pinpoint Test A : The PTBA (Pro Trailer Backup Assist) Control Knob Status Indicator Is Inoperative Or Always Illuminated

WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The engine needs to be running for the PTBA system and PTBA control knob status indicator to function.

A1 VERIFY THE CONCERN

Start the engine

Verify the operation of the PTBA system.

Press the PTBA button.

Select the correct trailer from the IPC display.

Does the PTBA control knob status indicator operate correctly?

Yes	The system is operating correctly at this time. The concern may have been caused by high network traffic or the driver's perception of how the PTBA system operate. Refer to the Owner's Literature.

GO to A2

A2 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE GWM (GATEWAY MODULE A) SELF-TEST
- Engine off
- Ignition ON.
- Using the diagnostic scan tool, perform the GWM self-test.
Are any Diagnostic Trouble Codes (DTCs) retrieved?

Yes See the GWM DTC Chart. REFER to: Communications Network .

No GO to A3

A3 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE PSCM (POWER STEERING CONTROL MODULE) SELF-TEST
- Using the diagnostic scan tool, perform the PSCM self-test.
Are any Diagnostic Trouble Codes (DTCs) retrieved?

Yes See the PSCM DTC Chart. Refer to EPAS GUIDED ROUTINE TESTING -- NAVIGATOR .

No GO to A4

A4 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE TRM (TRAILER MODULE) SELF-TEST

Using the diagnostic scan tool, perform the TRM self-test.

Are any Diagnostic Trouble Codes (DTCs) retrieved?

Yes	REFER to DTC Chart: TRM .

No	If the PTBA control knob status indicator is inoperative, GO to A5If the PTBA control knob status indicator is always illuminated, GO to A9

A5 BYPASS THE TRM (TRAILER MODULE)

Ignition OFF.

Disconnect TRM C2498C .
NOTE: If the jumper wire fuse fails during this step, refer to the Wiring Diagrams manual to identify the possible causes of the circuit short.

Connect:

Positive Lead	Measurement / Action	Negative Lead
C2498C-6	Courtesy of FORD MOTOR COMPANY	Positive Battery Terminal

Does the PTBA control knob status indicator illuminate?

Yes	REMOVE the fused jumper wire. GO to A10

No	REMOVE the fused jumper wire. GO to A6

A6 CHECK THE PTBA (PRO TRAILER BACKUP ASSIST) CONTROL KNOB INDICATOR CIRCUIT FOR A SHORT TO GROUND

Disconnect PTBA Control Knob C2599 .

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2599-7	Courtesy of FORD MOTOR COMPANY	Ground

Is resistance greater than 10, 000 ohms?

Yes

GO to A7

No	REPAIR the circuit.

A7 CHECK THE PTBA (PRO TRAILER BACKUP ASSIST) CONTROL KNOB STATUS INDICATOR CIRCUIT FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2599-7	Courtesy of FORD MOTOR COMPANY	C2498C-6

Is the resistance less than 3 ohms?

Yes

GO to A8

No	REPAIR the circuit.

A8 CHECK THE PTBA (PRO TRAILER BACKUP ASSIST) CONTROL KNOB GROUND CIRCUIT FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2599-6	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes	INSTALL a new PTBA control knob. REFER to: Pro Trailer Backup Assist Control Knob .

No	REPAIR the circuit.

A9 CHECK THE PTBA (PRO TRAILER BACKUP ASSIST) CONTROL KNOB STATUS INDICATOR CIRCUIT FOR A SHORT TO VOLTAGE

Ignition OFF.

Disconnect TRM C2498C .

Disconnect PTBA Control Knob C2599 .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C2599-7	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage present?

Yes	REPAIR the circuit.

GO to A10

A10 CHECK FOR CORRECT TRM (TRAILER MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all TRM 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 TRM 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 TRM.

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