04-23-2010, 07:43 AM
Join Date: Apr 2010
Mein Auto: 528i
e39 BMW 528i ABS Control Module DIY and Case Study
Vehicle: 2000 BMW 528i with DSC
Symptoms: After the car heated up to operating temperature the ABS light, Brake light, Check Engine light would turn on. In addition the speedometer would stop working, and any display or indicator requiring speedometer functionality also stopped working, including trip meter, odometer, fuel efficiency meter, etc.
Local independent repair shop with good reputation and award winning service determined through diagnostics that it was the ABS Control Module, after having replaced the rear speed sensor. Quoted a price of $1,600 to replace and reprogram Bosch 5.7 ABS Control Module.
After brief research found that there were choices and alternatives.
1. Buy a used control module for around $375, some are available with a 6 month warranty. The service shop agreed to install used part but it would have to be reprogrammed by BMW for $129. Total cost $504. BMW tech said that ABS Control module cannot be reprogrammed, they can only be programmed once as a new module.
Can anyone corroborate this? Could Bosch really be that stupid/greedy as to use a chip that can only be programmed once? If you know anything please provide details.
By the way if choose this route make sure you get the part number off the sticker on the bottom of the existing Control Module as the part numbers must be the same.
2. Have the existing control module rebuilt by one of the automotive electronics rebuilding services. Costs around $300-$400 including shipping back and forth. Based on conversation with a very helpful lady at http://www.modulemaster.com they can be rebuilt and actually end up being better quality than the original.
She indicated that there are some that are damaged beyond repair and that if that is the case they will sell you another rebuilt one for an additional $75 if they have any in stock. Module Master offers a 5 year warranty for the rebuilt one.
3. Buy a brand new one from any number of online parts shops for around $450-$550. These usually come with a 1 year warranty.
I'm going with option 2 to have it rebuilt because there is an 85% chance that they can rebuild it better than before, and I plan on keeping this car for a while and a 5 year warranty on this part sounds good.
The reason it went bad in the first place is because the internal wiring seems to be too thin or of poor quality. After repeated heating and cooling shorts out.
In any event for $1,600 one can buy one hell of a laptop, can't bring myself to spend that kind of money on a low level electronic component.
Heading to the garage to remove the control module from the pump unit. Will add more later.
Removing ABS Control Module:
The control module is located on the passenger side. There is a metallic box, which is the pump, with tubes coming out of it. The control module is attached to the front of the pump.
The first step is to remove the connector. The image above shows the connector with the locking mechanism in the closed position. The image below shows the connector with the locking mechanism in the open position. To unlock the connector gently slide the locking mechanism toward the engine.
Carefully lift the connector straight up to disconnect it from the control module. The contact points are very thin pins and you'll want to make sure not to bend them.
Next use a #20 torx tip to remove the six bolts that mount the control module onto the pump. Once the bolts are removed, carefully slide the control module towards the front of the car. The arrows in the picture below give a reference of where the bolts are located. They were pretty easy to access.
Cover the surface where the control module was mounted with foil. I also covered the connector to prevent dirt from getting in there as well.
The image below shows what the control module looks like inside. Pretty nifty piece of work, and very delicate so handle with care.
To ship it I imagine shipping an egg. I lightly put some tape over the cylinders from one side of the frame to the other. The cylinders have some wobble and the tape should keep them stable during shipping.
Next i wrapped the whole thing in aluminum foil as instructed by rebuilding service. Wrapped the whole thing in bubble wrap and used a large enough box so there would be at least 4 inches of packing peanuts surrounding it.
And away it goes.
It will be a few days before rebuilding service gets it. More later.
Last edited by BAMF; 04-26-2010 at 11:55 AM.
Reason: Added images and more