'14 Explorer Code P188B AWD Clutch Control Circuit Issue

[giantsfan]

Hi everyone! I have a '14 Explorer Limited 4WD with at 3.5L non-turbo engine. It has just over 80k miles.

Yesterday on the first start of the day, I put it in reverse and a warning popped up that said "Check AWD", a wrench came on, and when I went to move the 4WD selector to see what was going on another warning said Terrian Management System Disabled. I drove it any way a short distance, maybe 5 miles to the store. When I started it back up everything was normal until I went into drive and that stuff popped up again. I got home and I hooked my scan tool. I got a Ford Code P188B for AWD Clutch Control Circuit. I cleared the code and went to drive it a few hours later with all the same issues. I did some research but there isn't much coming up for this problem. I scrubbed this forum but I could not find anything related to this problem.

Some background info:
- tires were replace 1 year ago
- PTU replaced in early '20
- PTU drained/filled in May '22 and done once a year since PTU replacement
- Tires rotated in May '22

Any help you can give me would be greatly appreciated!

 

[ProjectSHO89]

The P188B has nothing to do with the PTU or the tires.

The DTC indicates there is an electrical circuit fault with the ATCC solenoid (in the rear differential), the AWD Relay module, the PCM, or the wiring between those components.

Diagnostic procedure in the service manual is pretty straight forward, a couple of resistance and voltage checks. If you have a meter and are comfortable using it, I can post them along with the schematic.

First level check would be to get under there and visually inspect the ATCC solenoid connector and wiring for anything obvious.

 

[giantsfan]

The P188B has nothing to do with the PTU or the tires.

The DTC indicates there is an electrical circuit fault with the ATCC solenoid (in the rear differential), the AWD Relay module, the PCM, or the wiring between those components.

Diagnostic procedure in the service manual is pretty straight forward, a couple of resistance and voltage checks. If you have a meter and are comfortable using it, I can post them along with the schematic.

First level check would be to get under there and visually inspect the ATCC solenoid connector and wiring for anything obvious.

ProjectSHO89 thank you for getting back to me. The reason I put that info in about the PTU was because in other forums about the warning lights those questions were asked first.
This seems like pretty straightforward troubleshooting. I will get under the truck and check ATCC solenoid to see if there is anything visibly wrong first. Would you mind posting the schematics? I do have a fluke meter so I can read out the wires.

 

[ProjectSHO89]

2014 Explorer Workshop Manual
Pinpoint Test D: P188B

Diagnostic Overview​

Diagnostics in this manual assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to Diagnostic Methods in Section 100-00 for information about these practices. This pinpoint test is intended to diagnosis the wiring, terminals, connectors, AWD relay and PCM.

NOTE: Fuse 70 (15A) is HOT at all times and protects multiple components. Check related systems that may be inoperative.

Refer to Wiring Diagrams Cell 34 , 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 energize the ATC solenoid.

DTC Fault Trigger Conditions

DTC ​	Description ​	Fault Trigger Conditions ​
P188B​	AWD Clutch Control Circuit​	When the PCM detects an open, a short to ground or voltage on the ATC solenoid voltage supply and/or return circuit.​

• Possible Sources
• Connectors damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals
• ATC solenoid
• PCM

PINPOINT TEST D: P188B

Test Step	Result / Action to Take
D1 CHECK THE ATC SOLENOID AND CONTROL CIRCUITS FOR AN OPEN WITH THE ATC SOLENOID CONNECTED
Disconnect: AWD Relay C4379. Inspect the connectors for damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals. Measure: Positive Lead​ Measurement / Action​ Negative Lead​ C4379-5​ C4379-8​ Is the resistance between 1 and 5 ohms?	Yes INSTALL a new AWD relay module. REFER to All Wheel Drive (AWD) Relay 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 D2 .
D2 CHECK THE ATC SOLENOID CIRCUITS FOR AN OPEN
Disconnect: ATC Solenoid C4347. Inspect the connector for damaged or pushed-out terminals, corrosion, loose wires and missing or damaged seals. Measure: Positive Lead​ Measurement / Action​ Negative Lead​ C4379-5​ C4347-1​ C4379-8​ C4347-2​ Is the resistance less than 5 ohms?	Yes GO to D3 . No REPAIR the circuit.
D3 CHECK THE ATC SOLENOID CIRCUITS FOR A SHORT TO GROUND
Measure: Positive Lead​ Measurement / Action​ Negative Lead​ C4379-5​ Ground--​ C4379-8​ Ground--​ Is the resistance greater than 10,000 ohms?	Yes GO to D4 . No REPAIR the circuit.
D4 CHECK THE ATC SOLENOID CIRCUITS FOR A SHORT TOGETHER
Measure: Positive Lead​ Measurement / Action​ Negative Lead​ C4379-5​ C4379-8​ Is the resistance greater than 10,000 ohms?	Yes GO to D5 . No REPAIR the circuit.
D5 CHECK THE ATC SOLENOID CIRCUITS FOR A SHORT TO POWER
Ignition ON. Measure: Positive Lead​ Measurement / Action​ Negative Lead​ C4379-5​ Ground--​ C4379-8​ Ground--​ Is any voltage present?	Yes REPAIR the circuit. No GO to D6 .
D6 CHECK THE ATC SOLENOID
Measure: Positive Lead​ Measurement / Action​ Negative Lead​ C4347-1​ C4347-2​ Is the resistance less than 10 ohms?	Yes INSTALL a new PCM. REFER to Section 303-14 . 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 Section 307-01B . PROGRAM the PCM with the ATC solenoid bar code information, REFER to Automatic Torque Coupling (ATC) Configuration . PERFORM the AWD Drive Cycle. No INSTALL a new rear axle. REFER to Section 205-02 . PROGRAM the PCM with the ATC solenoid bar code information. REFER to Automatic Torque Coupling (ATC) Configuration . PERFORM the AWD Drive Cycle.

 

[ProjectSHO89]

 

[giantsfan]

ProjectSHO89 this is great info! I plan on starting to look everything over this evening or tomorrow. When I find something will let you know.

 

[ProjectSHO89]

I'd be very interested if you document your readings and observations for each step in the pinpoint. Haven't seen this one traced out before.

 

[giantsfan]

I'd be very interested if you document your readings and observations for each step in the pinpoint. Haven't seen this one traced out before.

I just printed out the instructions so as I go to each step I will document my readings on the pages I printed. I hope I don't have to dig to deep because it looks like I will have to remove some interior panels to get to the AWD relay module. If I'm not mistaken, the PCM is located under the window cowl, is that correct?

 

[giantsfan]

ProjectSHO89 thank you for all your help and getting me the troubleshooting procedures for this problem. I worked on this today. I got the truck on jack stands and I started looking at the ATCC solenoid first. I made my way down inspecting the harness and I found this:

I'm not sure how this happened. There is a section missing so I'm thinking maybe a squirrel ate it or it broke off driving. I spliced in a new wire and it's good to go! The biggest pain was getting the harness out and in. It's on top rear differential and there isn't much room to get your hands in to disconnect the connectors and get the clips undone to free the harness.

The only reading I took was the resistance reading after I spliced in the new wire. The ATTC wires read out to be 2 ohms which is good since it had to be less than 5 ohms.

Again thank you for all your help!! It is very much appreciated! I owe you big time!

 

[ProjectSHO89]

Happy to help out!

Damned varmints!

 

[knuckles14]

The P188B has nothing to do with the PTU or the tires.

The DTC indicates there is an electrical circuit fault with the ATCC solenoid (in the rear differential), the AWD Relay module, the PCM, or the wiring between those components.

Diagnostic procedure in the service manual is pretty straight forward, a couple of resistance and voltage checks. If you have a meter and are comfortable using it, I can post them along with the schematic.

First level check would be to get under there and visually inspect the ATCC solenoid connector and wiring for anything obvious.

I have this same code on my 2015 Ford explore sport. Can I still drive with code on?

 

[javaleo]

Get some Rodent Repellent and spay the engine bay and under the car where there are wires.

 

[giantsfan]

I have this same code on my 2015 Ford explore sport. Can I still drive with code on?

Knuckles, I don't see why you couldn't, but in wouldn't suggest doing it for a long period of time. You will not have AWD, you will only have FWD when the code comes on and you will loose any of the terrain selections(ie 4WD).

 

[TechnoViking]

I've been trying to find a solution to my problem for days....
Little backstory: Bought a 2018 Explorer Sport in Denver on the 1st of april. Car was hail damaged, but fixed.
4 days after I get it home, alternator goes out. Barely getting the car home, basically everything shuts down but the motor. New alternator installed, 3 days alter I get a "4WD malfunction" with the terrain selection unavailable message.
Code is p188B.
I've been trying to follow the troubleshooting schematic, but now I can't get a resistance reading in the wiring from the AWD module, nor the ATCC Solenoid.

I did however bust open the diff, the fluid was nice and chalky, with shavings in it and stuck to the magnetic drain bolt.......

I'm at a loss....
Car still drives and pulls like crazy, but I hate that I don't have 4wd due to it snapping into "limp" mode with the trans....

Help!

 

[TechnoViking]

Little update:
It was actually the Clutch Control Solenoid, something my scan tools were telling me all along. But in order to fix it, the whole rear-diff had to be changed, because the solenoid was mounted in there, on the top of it. I had a feeling it was going to be that, even after all my voltage and resistance checks.

fairly inexpensive, dealer wanted 1k for it, plus labor, we did it for 440 out the door. code hasnt come back yet.

I've been trying to find a solution to my problem for days....
Little backstory: Bought a 2018 Explorer Sport in Denver on the 1st of april. Car was hail damaged, but fixed.
4 days after I get it home, alternator goes out. Barely getting the car home, basically everything shuts down but the motor. New alternator installed, 3 days alter I get a "4WD malfunction" with the terrain selection unavailable message.
Code is p188B.
I've been trying to follow the troubleshooting schematic, but now I can't get a resistance reading in the wiring from the AWD module, nor the ATCC Solenoid.

I did however bust open the diff, the fluid was nice and chalky, with shavings in it and stuck to the magnetic drain bolt.......

I'm at a loss....
Car still drives and pulls like crazy, but I hate that I don't have 4wd due to it snapping into "limp" mode with the trans....

Help!