Ford cars that come with 4WD or AWD systems allow you to feel more comfortable on the road. Stability and handling improve greatly with the all-wheel-drive option. However, the fact that you have more engineering units in your car leads to the fact that you get a higher chance of errors and problems.
Whenever you see the “4WD Fault, Service Required” error message, you should stop the vehicle. While, in most cases, the problem shows just a minor software glitch or electrical problem, sometimes, the issues may be much more serious.
But in the article, I will tell you how to check it right away and understand if you still can drive.
What can trigger the “4WD Fault, Service Required” message?
This message is triggered by a bunch of codes in several electronic control units that cover the operation of the powertrain in your Ford. Usually, the control units don’t get the proper signal from one of the sensors and trigger this message.
In some cases, it’s possible to clear the message (and the code) by just restarting the engine. But, in many cases, the annoying message will pop up again after 15-20 miles of driving. By the way, it’s like the “AWD High Temp” message in Nissan that I’ve already written about.
Here are the reasons that can cause this problem:
1) Software glitch
This is the most desired reason that can cause this message to appear on your dash. If this is just the problem with the software, the problem will be solved after restarting the engine. And you will not see the message again.
If the issue is in the hardware, you can also solve it by restarting the car but it will reappear. This way, you can understand if the core issue is with some software.
2) Half-shaft sensor problems
Your AWD or 4WD system gets the readings of all half-shaft sensors. This allows the system to make proper conclusions about the road type and engage the 4WD automatically when needed.
If the readings from these sensors are unusual, the system may eventually throw some codes and you will see the 4WD message on your dash.
Also, half-shaft sensors have proved to be unreliable in Ford vehicles made after 2012, especially in the Ford Edge. So, this is obviously one of the first things you should check and diagnose.
3) Wiring issues
These problems are extremely common when you are driving a lot in off-road conditions. Some stone or other obstacle may easily damage wires that connect sensors with electronic control units. In this case, the error message will be constant whatever you do.
Locating and fixing wiring problems is not that easy. You will obviously need professional help with this.
4) Low transmission fluid level
In your 4WD system, there are several units that have fluids in them. The transmission is the first one and it can actually throw the 4WD error when the fluid is low. Also, the differentials and transaxle units have fluids in them. If you constantly see the 4WD error message, it’s worth checking the fluid levels.
Don’t forget that your Ford has certain recommended intervals for fluid change. It’s better to change transmission and differential fluid when recommended. Otherwise, it can stop doing its job and you will see some codes and messages.
5) Temporary harsh road conditions
When your wheels slip or the stability is lost for some time, your Ford vehicle may go a little crazy. One of the possible consequences of this is that one of the wheels slipped on ice or in the snow.
Also, this message may have popped up shortly because of your Ford losing its traction on ice. When your vehicle moves without any control, goes into a skid, etc., all the systems in the vehicle do everything possible to avoid total loss of control. This will include some systems throwing errors because of their inability to do anything.
In this case, you will just need to keep driving carefully and the message will disappear when the road conditions are normal again.
6) Overheated 4WD units
If your vehicle is in off-road conditions and the wheels keep spinning and slipping, chances are the differentials and the transmission unit are overheating. In this case, you may just lose these units after several minutes of such driving.
Of course, the best option in this case is to stop the vehicle, turn off the engine, and figure out how you can move further without causing damage to your transmission systems.
What can help you diagnose the issue immediately?
First of all, pay attention to other error messages and warning lights. If there are some, they will help you narrow down the list of possible issues.
Also, a good scanner will help you get the codes. After googling the codes, you will understand which exact unit is malfunctioning.
Just observing the vehicle is another option. You can drive very carefully and find the pattern that triggers the message. But do this only in cases when you are sure the transmission is absolutely safe.
How can you fix the problem?
To fix the problem, you may want to try several DIY methods that may work with zero costs on your side.
Here’s what you may try doing:
1) Turn the engine off and then on again.
It may sound funny but it may actually work. You will reset the system, it will communicate with all the sensors again and the problem may be gone. If you are lucky enough.
2) Disconnect the battery for 5-7 minutes
Disconnect the negative terminal and then the positive one. Wait for 5-7 minutes and reconnect the battery. In this case, the control unit will communicate with all the sensors to gather the needed data. If the problem was in the software, it may just disappear. Or at least, you will have several miles without the error message.
3) Stop the car and let the units cool down
If the problem is in harsh driving conditions, you may need to stop the vehicle and let everything cool down. Then try driving carefully and make sure your wheels don’t slip and you don’t lose traction. If the message reappears, there is a more serious problem.
4) Use the scanner and get the codes
You may use the scanner to read the codes and understand what exactly causes problems. Sometimes, this will help you understand that a certain sensor requires replacement. By diagnosing the vehicle this way, you may save several hundred dollars.
But before you replace the sensor, make sure you verify it malfunctions. You may need to read more information in forums or talk with a good mechanic.
If nothing works, your Ford may need to go to the dealership or to a good repair shop. This is not the most common problem with Ford vehicles, so it may take some time for mechanics to understand what’s going on with your car.
Can you still drive when you see this message?
Usually, the “4WD Fault, Service Required” error message doesn’t mean anything really serious. But I strongly recommend against ignoring it. Even if you don’t want to check all the units and apply all the DIY methods I listed above, you should at least stop the vehicle and let all the units cool down properly.
If you keep driving with an overheated differential or low transmission fluid, there is a high chance that you will eventually need to pay literally thousands of dollars for their replacement.
So, no, don’t drive, and never ignore this message. But following the simple steps listed above will help you quickly understand whether it’s something serious or just a problem with the software.
Do you have experience dealing with this error message in Ford vehicles? Write in the comments and let other people know!