PSCM Circuit Information

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Refer to Power Steering Controls wiring diagrams for schematic and connector information.

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

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

Fig 1: PSCM-B Connector - C225B

Courtesy of FORD MOTOR CO.

Harness Side

CIRCUIT AND PIN DESCRIPTION

Circuit

BP1: RECHECK THE PSCM DTCS

Ignition ON, engine running.
Carry out the PSCM self-test.
Is DTC B1304:68 currently present and active in the PSCM?

Yes	No
Go to BP2.	The system is operating correctly at this time. The DTC may have set due to a previous low battery voltage condition (low battery state of charge).

BP2: CHECK THE VEHICLE BATTERY AND CHARGING SYSTEM VOLTAGE

Ignition ON, engine OFF.
Refer to the Charging System General Information article and carry out Pinpoint Test A: Battery Condition Test (battery state of charge).
Did the battery pass the condition test (battery state of charge)?

Yes	No
Go to BP3.	INSTALL a new 12-volt battery. REFER to the Battery, Mounting and Cables article.

BP3: CHECK THE PSCM VOLTAGE SUPPLY

Ignition OFF.
Measure the voltage between:

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

Record the measured battery voltage.
PSCM_B connector disconnected. (C225B)
Measure the voltage between:

(+) PSCM_A (C225A) Connector, Harness Side	(-)
B+	Ground

Measure the voltage between:

(+) PSCM_B (C225B) Connector, Harness Side	(-)
IGN START/RUN	Ground

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

Yes	No
Go to BP4.	VERIFY the PSCM fuses in the BJB and the high-current BJB are OK. If the fuses are OK, REPAIR the circuit. If the fuses are not OK, REFER to the Wiring Diagrams article to identify the circuit short.

BP4: CHECK THE PSCM GROUND CIRCUIT FOR AN OPEN

Ignition OFF.
Disconnect the battery negative cable. Refer to the Battery Disconnect General Procedure in the Battery, Mounting and Cables article.

Measure the resistance between:

(+) PSCM_A (C225A) Connector, Harness Side	(-)
GND	Ground

Is the resistance less than 3 Ohms?

Yes	No
Go to BP5.	REPAIR the circuit.

BP5: VERIFY PSCM POWER AND GROUND CONNECTIONS

Using a good light source, inspect all PSCM electrical connectors for:
- corrosion - install a new connector or terminal and clean the module pins.
- damaged or bent pins - install new terminals or pins.
- pushed-out pins - install new pins as necessary.
- spread terminals - install new terminals as necessary.
PSCM_B connector connected. (C225B) Make sure the connector seats and latches correctly.
Connect the battery negative cable. Refer to the Battery Disconnect General Procedure in the Battery, Mounting and Cables article.
Ignition ON, engine OFF.
Clear the PSCM DTCs.
Ignition ON, engine OFF.
Ignition ON, engine running.
Carry out the PSCM self-test.
Is DTC B1304:68 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 BP6.	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.

BP6: VERIFY PSCM WIRE HARNESS POWER AND GROUND CONNECTIONS

Ignition OFF.
Disconnect and inspect the PSCM ground joint connection, clean or repair as necessary. Refer to Power Steering Controls wiring diagrams ground joint information.
HC-BJB_B Assembly connector disconnected. (C1617B)
Inspect the high-current BJB connection, clean or repair as necessary. Refer to Power Steering Controls wiring diagrams high-current BJB joint information.
Connect the PSCM ground joint connection. Make sure the connection is clean, tight and not cross-threaded.
HC-BJB_B Assembly connector connected. (C1617B) Make sure the connection is clean, tight and not cross-threaded.
Ignition ON, engine OFF.
Clear the PSCM DTCs.
Ignition OFF.
Ignition ON, engine running.

Carry out the PSCM self-test.

Is DTC B1304:68 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 BP7.	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.

BP7: VERIFY PSCM HARNESS FOR INTERMITTENT 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.
NOTE: If the scan tool cannot display the PID reading due to no communication with the PSCM, select the No Action.
Do the measured battery voltage and the PID display differ by more than 1.5 volts?

Yes	No
INSTALL a new PSCM wiring harness. Go to BP8.	Go to BP10.

BP8: VERIFY NEW PSCM HARNESS FOR INTERMITTENT 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.
NOTE: If the scan tool cannot display the PID reading due to no communication with the PSCM, select the No Action.
Do the measured battery voltage and the PID display differ by more than 1.5 volts?

Yes	No
Go to BP10.	Go to BP9.

BP9: CHECK THE PSCM FOR DTC B1304

Ignition ON, engine OFF.
Clear the PSCM DTCs.
Ignition OFF.
Ignition ON, engine running.
Operate the system.
Carry out the PSCM self-test.
Is DTC B1304:68 currently present and active in the PSCM?

Yes	No
Go to BP10.	The repair is complete.

BP10: CHECK FOR APPLICABLE SERVICE ARTICLES

Ignition OFF.
Check OASIS for any applicable TSB, GSB, SSM or FSA.
Does a service article exist for PSCM DTC B1304:68?

Yes	No
DISCONTINUE this test and FOLLOW the service article instructions.	DIAGNOSE the charging system. REFER to the Charging System - General Information article. The PSCM wiring harness, related circuits and connectors are NOT a root cause for the PSCM DTC B1304. DTC B1304 DOES NOT require a new PSCM to be installed.