Wagoneer2001

I own a 2001 E320 4matic Wagon.

My wife backed down a steep driveway and dropped the left front and left rear off the pavement into 6-inch deep mud. When she tried to go forward again the left front and left rear tires spun but the car didn't move.

I thought 4matic was supposed to apply brakes to the spinning tires to transfer torque to the ones on pavement so at least the car could move forward. Is this normal?

There are no lights on the dash.

We recently replaced the front axle/CV joints. Is there something the mechanic forgot to put back to make the 4matic work correctly?

Figuero

Sounds like your ETS might not be engaging. Don't expect 4wd performance from a 4Matic but you should at least have seen a flashing light and heard the ABS being applied, along with the throttle being retarded.

In your situation though, my guess is that you would remain stuck in the mud. The center differental is an open design and it will send equal torque to each axle. It would be nice if the system would firmly apply the brake to the spinning wheel(s) and tranfer all the torque to the wheels with traction side to side and and front to rear, but it won't. It will just chatter away. It's good for slippery on road conditions, but it's not meant to be an off road system. But you would be very aware of it's operation. Lights, vibration, and sound.

There is an interesting video that demonstrates various AWD systems by using a ramp with rollers. It doesn't demo the 4Matic, but it clarifies what I'm trying to say.

number_one_c55

YES this is normal - if there are any problems you will get a ABS - BAS - ESP warning indicators on. You have nothing to worry about. If you live in slippery conditions like snow and the ESP is activated all the time you will eat through brakes like you wont believe.

Figuero

Actually it's not normal. If you read the OP - He doesn't have any warning indicators. He should be seeing the flashing yellow triangle. Something isn't right.

number_one_c55

At this moment in time there is nothing noted about the ASR light flashing - his wife was driving. If wheel was spinning uncontrollably there will be ABS - ASR - BAS light on indicating a problem. The sensor that controls the speed of the wheels and where the ABS is applied is the wheel speed sensor, if wheel speed sensor actual values are off what so ever you will get a warning indicator. If no ABS - ASR - BAS lights are present please check that ASR light BULB in rear of cluster is not burnt out.

number_one_c55

Easy way to make sure all instrument cluster bulbs are working correctly - turn key to key position 2 make sure all lights come on - refer to link. Link cluster is out of a W220 S-Class.

http://www.modulemaster.com/en/image...-class_big.jpg

*** PLEASE REFER TO PAGE 229 OF YOUR OWNERS MANUAL ***
Notes:

The malfunction indicator lamp for the ESP is combined with that of the BAS.

The yellow BAS/ESP malfunction indicator lamp in the instrument cluster and the yellow ESP warning lamp int he speedometer dial come on with the electronic key in steering lock position 2. They should go out with the engine running.

If the BAS/ESP malfuntion indicator lamp comes on continuously with the engine running, a malfuntion has been detected in either system. Only partial engine output will be available.

If the BAS malfuntions, the brake system functions in the usual manner, but without BAS.

If the ESP warning message is displayed, have the BAS or ESP check at your authorized Mercedes-Benz Center as soon as possible.

With the ABS malfunctions, the ESP is also switched off.

livetodrive

After the two rear wheels of my E430 4-Matic slipped on ice and the front wheels didn't turn, I took it to the dealer. They repaired the transfer case under warranty. I haven't had this problem since then.