Pinpoint Test D: DTC P188C And P188D

WARNING: This page is about a different variant/trim than selected.

D1 CHECK FOR AWD RELAY VOLTAGE

Ignition OFF.
Disconnect: AWD Relay Module C4379.
Inspect the connectors for damaged or pushed out terminals, corrosion, loose wires and missing or damaged seals.
Ignition ON.

Measure the voltage between.

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
C4379-1	CBB70 (YE/BU)	-	Ground

Fig 1: Identifying C4379 Connector Terminals

Courtesy of FORD MOTOR CO.

Is the voltage greater than 11 volts?

Yes : GO to D4.
No : GO to D2.

D2 CHECK FUSE 70 (10A)
- Ignition OFF.
- Remove fuse 70 (10A).
- Check fuse 70 (10A).
- Is the resistance less than 5 ohms?
- Yes : GO to D3.
- No : REPAIR the circuit.

D3 CHECK THE AWD RELAY POWER CIRCUIT FOR AN OPEN

Measure the resistance between.

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
C4379-1	CBB70 (YE/BU)	BJB	CBB70 (YE/BU)

Fig 2: Identifying C4379 Connector Terminals

Courtesy of FORD MOTOR CO.

Is the resistance less than 5 ohms?

Yes : GO to D5.
No : REPAIR the circuit.

D4 CHECK THE AWD RELAY GROUND CIRCUIT FOR AN OPEN

If removed, install fuse 70 (10A)
Ignition ON.

Measure the voltage between.

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
C4379-1	CBB70 (YE/BU)	C4379-4	GD151 (BK/GN)

Fig 3: Identifying C4379 Connector Terminals

Courtesy of FORD MOTOR CO.

Is the voltage greater than 11 volts?

Yes : GO to D5.
No : REPAIR the circuit.

D5 CHECK THE AWD RELAY MODULE COMMAND AND FEEDBACK CIRCUITS FOR AN OPEN

Ignition OFF.
Disconnect: PCM C175B.

Measure the resistance between.

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
C4379-3	VCF35 (GN)	C175B-54	VCF35 (GN)
C4379-6	VCF34 (WH)	C175B-3	VCF34 (WH)

Fig 4: Identifying C4379 And C175B Connector Terminals

Courtesy of FORD MOTOR CO.

Is the resistance less than 5 ohms?

Yes : GO to D6.
No : REPAIR the circuit.

D6 CHECK THE AWD RELAY MODULE COMMAND AND FEEDBACK CIRCUITS FOR A SHORT TO GROUND

Measure the resistance between.

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
C4379-3	VCF35 (GN)	-	Ground
C4379-6	VCF34 (WH)	-	Ground

Fig 5: Identifying C4379 Connector Terminals

Courtesy of FORD MOTOR CO.

Is the resistance greater than 10, 000 ohms?

Yes : GO to D7.
No : REPAIR the circuit.

D7 CHECK THE AWD RELAY MODULE COMMAND AND FEEDBACK CIRCUITS FOR A SHORT TOGETHER

Measure the resistance between.

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
C4379-3	VCF35 (GN)	C4379-6	VCF34 (WH)

Fig 6: Identifying C4379 Connector Terminals

Courtesy of FORD MOTOR CO.

Is the resistance greater than 10, 000 ohms?

Yes : GO to D8.
No : REPAIR the circuit.

D8 CHECK THE AWD RELAY MODULE COMMAND AND FEEDBACK CIRCUITS FOR A SHORT TO POWER

Ignition ON.

Measure the voltage between.

Positive Lead		Negative Lead
Pin	Circuit	Pin	Circuit
C4379-3	VCF35 (GN)	-	Ground
C4379-6	VCF34 (WH)	-	Ground

Fig 7: Identifying C4379 Connector Terminals

Courtesy of FORD MOTOR CO.

Is any voltage present?

Yes : REPAIR the circuit.
No : REPLACE the AWD relay module. REFER to ALL WHEEL DRIVE (AWD) RELAY MODULE . RUN the self-test. If DTC P188C and/or P188D return, INSTALL a new PCM, REFER to ENGINE CONTROLS - ELECTRONIC ENGINE CONTROLS . PROGRAM the PCM with the latest calibration. PERFORM the Solenoid Body Strategy Data Download procedure and PERFORM the Solenoid Body Strategy Drive Cycle, REFER to AUTOMATIC TRANSMISSION - 6F50/6F55 . PROGRAM the PCM with the ATC solenoid bar code information, REFER to AUTOMATIC TORQUE COUPLING (ATC) CONFIGURATION .