What Is The Service All Wheel Drive

Learn to Diagnose Why Your AWD Isn't Working

So you're having all-bicycle drive problems? C0407 sym64 on your OBDII is a code that is stored in the rear differential clutch command module (CCM) when the all-bike-bulldoze oil pump starts slipping due to depression oil. Oftentimes, the lawmaking appears after diagnosing the "service rear beam" bulletin on the dash. It can crusade the all-cycle-drive system to become disabled.

When this happens, you'll only have power going to the front end wheels. You'll need to trace the problem before you try to set information technology. From where the transfer instance connects to the front axle shafts, you have a driveshaft that goes to the rear of the vehicle. It connects to a rear differential which then connects to the beam shafts that power the rear wheels. This is as proficient of a identify as any to get-go when diagnosing all-cycle-bulldoze problems.

checking rear differential for AWD problems

The rear differential associates has 2 sides. One side has the clutch and the other the rear differential. The two are separated by a seal. Depending on the type of machine you drive, the rear differential clutch control module is located right adjacent to this associates and is mounted to the differential clutch pump.

In one case the control module receives a signal that the rear axle is engaged or disengaged, it activates or deactivates the pump to control the delivery of hydraulic oil pressure.

Ideally, the rear differential clutch control module will conciliate the clutch pump motor when the pressure reaches about 464 psi. This is when the appropriate system pressure has been reached. It then activates the differential clutch pump when the force per unit area goes beneath 392 psi. You'll get a C0407.64 code when the oil drops below its recommended level.

Possible Symptoms of All-Wheel-Drive Problems

The most common symptoms include:

Service Rear Axle alert bulletin
Service Engine Soon warning lite or check engine light
Anti-Lock Brake System warning lite

Causes of C0407 Code

There are a couple of reasons why the differential clutch fluid could be low. They include:

An external leak on the differential clutch
Oil leaking from the differential clutch and into the rear differential
Improper filling during a pump replacement or gasket service
Bad differential clutch pump

How to Diagnose and Set C0407 Code

The differential assembly should ever be properly filled. When filling it with fluid, it'due south important to annotation that the rear differential side is separate from the differential clutch side. The two use different types of fluid.

checking oil level for rear differential for all wheel drive problems

The rear differential comes with a drain plug and fill plug that y'all can employ to refill the oil. All you demand to practice is remove the latter and so remove the former to drain the existing fluid. Once done, you'll need to screw the bleed plug back in and add together some new oil through the fill plug. This fix applies when you've confirmed that the fluid is indeed low. However, if you remove the fill plug and notice that the fluid level is fine, you can move on to the differential clutch.

In certain situations, you may see gear oil coming out of the fill plug when servicing the rear differential. This oftentimes means that the seal that separates the differential clutch from the rear differential has failed. A bad seal causes fluid to move from the sometime to the latter, hence, the reason why you'll find gear oil coming out of the fill plug.

The differential clutch comes with a level plug from where you can bank check the level of the clutch fluid. You should not employ it to add fluid. If you do, the oil will non reach all the areas of the differential clutch.

You'll need to remove the vent hoses first to add fluid to the clutch assembly. A C0407 code occurs mostly when the pump is unable to pump fluid into the clutches to engage them. The fluid could be low or you could be simply having a bad pump.

One time you lot're done topping fluid in your differential, showtime the engine and let your car sit idle for five minutes in Park. Yous'll need to push the accelerator to wide-open throttle five times to purge the air out of the pump. Once you've completed this procedure, shut the vehicle off and check the fluid level over again.

Take a drain bucket just below every bit you lot remove the level plug on the differential clutch. If no fluid comes out, you'll need to add together some through one of the vent hoses once again. Having a rubber hose that you can install where the vent hose goes and a fluid transfer gun makes the piece of work easier.

This should help fix your code C0407 problem. Call back to check your fluid once more after driving a few thou miles. If it still runs depression, yous may need to supplant the seal.