PINPOINT TEST Y : The PSCM Does Not Respond To The Diagnostic Scan Tool

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery, Mounting and Cables .

Y1 CHECK THE PSCM VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

Ignition OFF.

Disconnect: PSCM C1463A and C1463B .

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1463A-2	Courtesy of FORD MOTOR COMPANY	Ground

Positive Lead	Measurement / Action	Negative Lead
C1463B-1	Courtesy of FORD MOTOR COMPANY	Ground

Are the voltages greater than 11 volts?

Yes	GO to Y2.
No	VERIFY the high current BJB Mega Fuse (125A) or BJB fuse 54 (5A) is OK. If OK, REPAIR the circuit in question. If not OK, REFER to the OEM Electrical Wiring Diagram Introduction to identify the possible causes of the circuit short.

Y2 CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN

Ignition OFF.

Disconnect: Negative Battery Cable.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1463A-1	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance less than 3 ohms?

Yes	GO to Y3.
No	REPAIR the circuit in question.

Y3 CHECK THE HS-CAN CIRCUITS BETWEEN THE PSCM AND THE DLC FOR AN OPEN

Measure:

Positive Lead	Measurement / Action	Negative Lead
C1463B-2	Courtesy of FORD MOTOR COMPANY	C251-6
C1463B-3	Courtesy of FORD MOTOR COMPANY	C251-14

Are the resistances less than 3 ohms?

Yes	CONNECT the negative battery cable. GO to Y4.
No	REPAIR the circuit in question. CONNECT the negative battery cable.

Y4 CHECK FOR CORRECT PSCM OPERATION

Ignition OFF.

Disconnect and inspect the PSCM connectors and related in-line connectors.

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

Reconnect the PSCM connectors and related in-line connectors. Make sure they seat and latch correctly.

Operate the system and verify the concern is still present.

Is the concern still present?

Yes	CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, discontinue this test and follow TSB instructions. If no TSBs address this concern, .
No	The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.