Pinpoint Test C : DTC P188B

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

Refer to All Wheel Drive (AWD) for schematic and connector information.

Normal Operation and Fault Conditions

The AWD system uses data from other systems as inputs to the PCM. The PCM uses the inputs to determine the appropriate time to send a signal and have the AWD relay module energize the Active Torque Coupling (ATC) solenoid.

DTC Fault Trigger Conditions

DTC	Description	Fault Trigger Condition
PCM P188B:00	All Wheel Drive Clutch Control Circuit: No Sub Type Information	When the PCM detects an open, a short to ground or voltage on the Active Torque Coupling (ATC) solenoid voltage supply and/or return circuit.

Possible Sources

Wiring, terminals or connectors
Active Torque Coupling (ATC) solenoid (part of the Rear Drive Unit (RDU))
Active Torque Coupling (ATC) Clutch
AWD relay module
PCM

Visual Inspection and Pre-checks

Active torque coupling (ATC) solenoid harness

C1 CHECK THE ACTIVE TORQUE COUPLING SOLENOID

Ignition OFF.

Disconnect Active Torque Coupling (ATC) Solenoid C4347.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3841-5	Courtesy of FORD MOTOR COMPANY	C3841-8

Is the resistance between 1 and 5 ohms?

Yes	INSTALL a new AWD relay module. Refer to: All-Wheel Drive (AWD) Module .

No	If the resistance is less than 1 ohm, repair the circuit for a short to ground. If the resistance is greater than 5 ohms, GO to C2

C2 CHECK THE ATC SOLENOID CIRCUITS FOR AN OPEN

Disconnect ATC Solenoid C4347.

Inspect the connectors for damaged or pushed out terminals, corrosion, loose wires and missing or damaged seals.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3841-5	Courtesy of FORD MOTOR COMPANY	C4347-1
C3841-8	Courtesy of FORD MOTOR COMPANY	C4347-2

Is the resistance less than 3 ohms?

Yes

GO to C3

No	REPAIR the circuit.

C3 CHECK THE ACTIVE TORQUE COUPLING SOLENOID CIRCUITS FOR A SHORT TO GROUND

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3841-5	Courtesy of FORD MOTOR COMPANY	Ground
C3841-8	Courtesy of FORD MOTOR COMPANY	Ground

Is the resistance greater than 10, 000 ohms?

Yes

GO to C4

No	REPAIR the circuit.

C4 CHECK THE ATC SOLENOID CIRCUITS FOR A SHORT TOGETHER

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3841-5	Courtesy of FORD MOTOR COMPANY	C3841-8

Is the resistance greater than 10, 000 ohms?

Yes

GO to C5

No	REPAIR the circuit.

C5 CHECK THE ATC SOLENOID CIRCUITS FOR A SHORT TO POWER

Ignition ON.

Measure:

Positive Lead	Measurement / Action	Negative Lead
C3841-5	Courtesy of FORD MOTOR COMPANY	Ground
C3841-8	Courtesy of FORD MOTOR COMPANY	Ground

Is any voltage detected?

Yes	REPAIR the circuits.

GO to C6

C6 CHECK THE ATC SOLENOID

Ignition OFF.

Measure the component side resistance between.

Positive Lead	Measurement / Action	Negative Lead
Courtesy of FORD MOTOR COMPANY C4347-1	Courtesy of FORD MOTOR COMPANY	Courtesy of FORD MOTOR COMPANY C4347-2

Is the resistance between 1 to 5 ohms?

Yes

GO to C7

No	INSTALL a new active torque coupling clutch. Refer to: Axle Assembly . PROGRAM the PCM with the ATC solenoid bar code information. Refer to: Active On-Demand Coupling Configuration . PERFORM the AWD Drive Cycle.

C7 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION

Ignition OFF.

Disconnect and inspect all PCM connectors.

Check for the following:
- 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 PCM 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, PCM Guided Routine Testing

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