2000ML320 taking out abs brain?
 

behind the fuse box there are two control units; the front is ESP and I believe the rear is ABS brain; I am wondering how in the dickens do you get those plugs off the top to remove the brain; I have replaced the fuse/relay/stop light switch and sent the control unit on the front of the pump off to be rebuilt, got it back rebuilt and still no abs light off. The code indicates ABS pump, going off the forum here, that seems unlikely so I thought I could send the brain off for checking. I just cannot get the darn plugs off. Thanks for any help.

ABS is part of the traction system, so is ESP. They are part of the same system & of the same computer.

ON that model there isn't a "control unit" on the hydraulic pump assembly.

Okay, there is the black box on the front of the pump that I sent off for assessing and rebuilding. The shop, usually reliable and trustworthy, gave this: C1401 indicates abs pump circuit. Power at the unit okay; applied direct power to pump, no operation. I am thinking they checked the plug in and there was power there, and then directly powered the black box on the front and got no power; after rebuild came back still getting same code even after 'clearing the computer', thoughts on this?

Verify that they unplugged the two pin connector that feeds the ABS pump motor and put power directly to the motor. If the motor doesn't run then it is just plain bad. Now if they put power to the black box from the ABS relay, and it doesn't get through to the motor, You have bad solder joints in the black box--see my ABS/ETS repair of this Search for jfreezn in this forum.

Regards,

Jim in Phoenix

You indicate a two pin connector supplying power to the abs motor; where do you find this? All I can find on the pump is the multi-pin; is it up on the 'brains' behind the fuses? David

Abs
 

Is your windshield washer reservoir the original one which is known to leak at the seam of the 2 halves and drip onto the ABS pump?

thanks for the idea, the ww tank is solid. One fellow wrote about directly jumping the pump itself by applying power to two wires and I cannot figure our which two; on the pump itself I only find the multipin connector on the right, looking down at the pump from in front. Does anyone know of which two wires he speaks? Great forum. David