A vehicle is a fine-tuned machine engineered with precision and different technologies. Since car manufacturers use different technologies in designing their cars, some problems are peculiar to certain cars.
For instance, we have 2WD, 4WD, and AWD cars. Problems like service all-wheel drive system are peculiar with all-wheel drive (AWD) vehicles. You will never see such a warning message on a two-wheel drive (2WD) vehicle.
What does it mean service all-wheel drive system?
The service all-wheel drive system warning message means the onboard computer has detected a problem with the all-wheel drive system. It could be caused by a faulty control module, overheated clutch control assembly, a low battery, contaminated rear differential fluid, or an incorrect tire size.
The all-wheel drive (AWD) system transfers power to all the wheels individually to maintain vehicle traction. The system uses a propeller to share power between the rear and front wheels.
A service all wheel drive system means the AWD system has been deactivated or not working, and power are not been distributed to the rear wheels. As a result, only the front wheels are powering the car. The warning can either flash intermittently or stay lit on the dashboard. In either case, it usually comes with a beeping sound.
What causes and how to fix service all-wheel drive system error
Generally, a service all wheel drive system light is typically caused by issues in the all wheel drive system and rear differential. Let’s have a breakdown of all the possible causes.
Incorrect tire size
Something as simple as installing a wrong tire size or not replacing all the tires at the same time can trigger the service AWD system warning message on the dashboard. This can confuse the traction control system, causing accelerated wear on the drivetrain.
The most feasible solution to this problem is to install the correct tire sizes. During tire replacement, change all the tires.
Whenever you notice the service all-wheel drive system message, start your inspection from the battery. The all-wheel-drive system needs adequate battery power to run optimally. If the battery charge drops too low, the all-wheel drive system may deactivate the rear wheels and display a service all-wheel drive system on the driver information center (DIC).
If the car computer displays the service all-wheel drive warning due to low battery, the car memory will log an error code C0550. The faulty code will be logged as a pending or stored diagnostic trouble code.
The solution is simple. All you need is to replace the dead battery with a new one. But if the battery is charged and the system still logs error code C0550, check your car’s electrical systems for parasitic drain.
Overheated clutch control assembly
An overheated rear differential clutch control module can trigger the service AWD message. The Clutch control assembly is responsible for transferring torque to the rear axle. The clutch module features a sensor that monitors the temperature and makes sure it stays within -40 degrees centigrade and +120 degrees centigrades.
The sensor constantly relays this data to the AWD system, which deactivates the rear wheels and triggers the service all wheel drive system on Chevy Trailblazer or any car model whenever the clutch control assembly overheats. The warning message will disappear, and the AWD system will start functioning once the temperature falls within the expected range.
On most vehicles, the rear differential has a control module that monitors how the system operates. The modules have electrical connectors. If the wiring connectors are corroded, it can trigger a service all-wheel drive system light on the dashboard.
The module connectors typically corrode due to their exposure to water and other road hazards like salts. Common knowledge will tell you that corrosion will eat away the connector pins, causing intermittent or no signal.
All you need to fix this problem is to apply dielectric grease on the connector pins to prevent damage. But if the damage is already done, then you have to replace the connectors.
Faulty control module
Speaking of the control module, the module itself can fail. When that happens, it will cause the service AWD system warning message to appear on the dashboard. The module can also short out due to exposure to water and other road hazards.
If you swim water with the module, clean it once you reach your destination and apply dielectric grease to prevent rust. If the module fails, the only feasible solution is to change it.
Dirty rear differential fluid
The differential fluid lubricates and cools the internal diff components. Over time, the fluid will become dirty and require to be changed. Most car manufacturers recommend changing the diff fluid every 150,000 miles.
The AWD system will pop up a service all wheel drive system on GMC or other vehicle models when the fluid becomes dirty. The warning light will be there until you change the diff oil.
Is it safe to drive with an AWD light on?
It is okay to be worried about your safety when you see the AWD light on your dashboard. Can you drive with it? If yes, for how long? Should you drive straight to a nearby mechanic shop for immediate inspection and rectifications?
The AWD light means the system is malfunctioning. However, it is absolutely safe to drive with the light on. Meanwhile, you must understand that once the AWD light is on, the system is malfunctioning, and the AWD has been deactivated.
So, forget about using the auxiliary gear when the AWD light is on because power are not transferring to the rear wheels. In other words, the transmission only distributes power on the front wheels. This is dangerous when driving in rain, snow, or off-road terrains.
While driving with an AWD light on is safe, do not ignore the problem. Driving with the light on means you are limited to certain terrains.
Keep in mind 2WD is only safe on city streets, dry pavement, and clear roads. It is unsafe to drive with it on gravel, ice-covered roads, and snow-covered roads.
How often should AWD be serviced, and what are its costs?
Car manufacturers have different inspection intervals. While automakers suggest that the diff fluid should be replaced at certain intervals, how often you should replace the AWD fluid depends on how often you drive and what type of fluid you use. Experts recommend changing the AWD fluid between 30,000 to 60,000 miles.
If you use conventional oil for your differential, you should replace it every 30,000 miles. But if you use a synthetic fluid, allow the vehicle to cover 60,000 miles before changing the fluid. However, it is important to note that some car manufacturers recommend changing the differential fluid after covering 150,000 miles.
Service all wheel drive system cost depends on three factors: the make and model of your car, the mechanic doing the job, and the maintenance task involved. That said, you can budget between $200 to $800 to service your AWD.
Service AWD System Light On YouTube
Once the service all wheel drive system warning appears on the dashboard, the vehicle switches from AWD to 2WD. More often than not, the warning pops up due to issues with the rear differential. However, other issues like incorrect tire size and low battery can be the culprit.
While driving with the warning light on can be absolutely safe, do not ignore fixing it because there are situations – rain, snow, and the likes – where it will be potentially unsafe to drive with the warning light on.