PSCM Circuit Information

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.

Refer to POWER STEERING CONTROLS , for schematic and connector information.

Refer to Steering GSB for additional connector and wiring inspection tips.

CAUTION: Use the correct probe adapters when making measurements. Failure to use the correct probe adapters may cause damage to the connector.

Fig 1: PSCM-A Connector End View (C1463A)

Courtesy of FORD MOTOR CO.

Harness Side

Circuit

Fig 2: PSCM-B Connector End View (C1463B)

Courtesy of FORD MOTOR CO.

Harness Side

Circuit

Fig 3: High-Current Battery Junction Box Connector End View (C1617D)

Courtesy of FORD MOTOR CO.

Harness Side

Circuit

M1: RECHECK THE PSCM DTCS

Ignition OFF.
Clear the PSCM DTCs.
Ignition OFF.
Wait at least one minute.
Ignition ON, engine running.
Carry out the PSCM self-test.

Is DTC U3004:49 present and active in the PSCM?

Yes	No
Go to M2.	The system is operating correctly at this time. The DTC may have set due to a previous low battery voltage condition.

M2: CHECK FOR CHARGING SYSTEM DTCS IN OTHER MODULES

Read DTCs from all modules.

Are any charging system DTCs present in both the PCM AND any other module?

Yes	No
DIAGNOSE the PCM DTC. REFER to the appropriate ELECTRONIC ENGINE CONTROLS - 3.5L ECOBOOST (272KW/370PS) .	Go to M3.

M3: CHECK THE BATTERY CONDITION AND STATE OF CHARGE

Carry out the Battery Condition Test. REFER to BATTERY, MOUNTING AND CABLES .

Does the battery pass the condition test?

Yes	No
Go to M4.	INSTALL a new 12-volt battery. REFER to BATTERY, MOUNTING AND CABLES .

M4: CHECK THE ABS MODULE VOLTAGE PID

Ignition ON, engine OFF.
Measure and record the 12-volt battery voltage.
Access the ABS and monitor the VPWR_ABS (VOLT) PID.

Is the PID display within 0.2 volt of the recorded battery voltage?

Yes	No
Using a diagnostic scan tool, CLEAR the PSCM DTCs. CARRY OUT the PSCM self-test. If there are no DTCs present in the PSCM, the system is operating correctly at this time. The DTC may have set due to a previous low battery voltage condition. If any U3003:XX DTCs are present in the PSCM, GO to PINPOINT TEST BX .	Go to M5.

M5: CHECK THE PSCM VOLTAGE SUPPLY

Verify all PSCM fuses are OK. If not OK, refer to Wiring Diagram Information to identify the cause of the circuit short.
Ignition OFF.
PSCM_A connector disconnected. (C1463A)
PSCM_B connector disconnected. (C1463B)
PSCM_C connector disconnected.
Ignition ON, engine OFF.

Measure the voltage between:

(+) PSCM_A (C1463A) Connector, Component Side	(-)
IGN START/RUN	Ground

Measure the voltage between:

(+) PSCM_C Connector, Harness Side	(-)
B+	Ground

Is each voltage measurement within 0.2 volt of the recorded battery voltage?

Yes	No
Go to M6.	REPAIR the circuit.

M6: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN

Ignition OFF.
Disconnect the battery negative cable. Refer to the General Procedure, Battery Disconnect in BATTERY, MOUNTING AND CABLES .

Measure the resistance between:

(+) PSCM_B (C1463B) Connector, Harness Side	(-)
GND	Ground

Is the resistance less than 3 Ohm?

Yes	No
Go to M7.	REPAIR the circuit.

M7: CHECK FOR CORRECT PSCM POWER AND GROUND JOINT OPERATION

Ignition OFF.
Disconnect and inspect the PSCM ground joint connection, clean or repair as necessary. Refer to Wiring Diagram Information POWER STEERING CONTROLS for ground joint information.
High-current Battery Junction Box connector disconnected. (C1617D)
Inspect the high-current BJB joint connection, clean or repair as necessary. Refer to Wiring Diagram Information POWER STEERING CONTROLS for high-current BJB joint information.
Connect the PSCM ground joint connection. Make sure the connection is clean, tight and not cross-threaded.
PSCM_A connector connected. (C1463A) Make sure the connector seats and latches correctly.
PSCM_B connector connected. (C1463B) Make sure the connector seats and latches correctly.
PSCM_C connector connected. Make sure the connector seats and latches correctly.
Ignition ON, engine OFF.
Clear the PSCM DTCs.
Ignition OFF.
Wait at least one minute.
Ignition ON, engine running.
Carry out the PSCM self-test.

Is DTC U3004:49 present and active in the PSCM?

Yes	No
The concern may be an intermittent condition with the PSCM wiring harness which cannot be detected by voltage or resistance checks. Go to M8.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded PSCM electrical connector or a wiring harness in-line electrical connector and was repaired during this procedure.

M8: CHECK FOR INTERMITTENT PSCM WIRING HARNESS POWER AND GROUND CIRCUIT OPERATION

Ignition ON, engine running.
Make sure the front wheels are on the ground and the vehicle is not being supported by other means.
- Make sure the front tires are clean and dry.
- Make sure the ground under the front tires is clean and dry.
Take the following measurement while turning the steering wheel back and forth, lock to lock, continuously at 1 revolution per second.

Measure the voltage between:

(+) 12 Volt Vehicle Battery	(-) 12 Volt Vehicle Battery
Positive terminal	Negative terminal

Record the measured battery voltage.
View the following PID while turning the steering wheel back and forth, lock to lock, continuously at 1 revolution per second.
Access the PSCM and monitor the MOD_SUP_V (VOLT) PID.
Compare the measured battery voltage with the PID display.

Do the measured battery voltage and the PID display differ by more than 1.5 volts?

Yes	No
INSTALL a new PSCM wiring harness.	The system is operating correctly at this time. The concern may have been caused by a loose or corroded PSCM electrical connector or a wiring harness in-line electrical connector and was repaired during this procedure.