The dreaded DSC problem with the E39, E46 and E38 model BMW is an extremely common one. The main symptom is that your DSC – or dynamic stability control- light may come on for a few minutes and then go away at random times. Eventually, the DSC light will stay on, no matter how many times you turn the car on and off or push the DSC button. You may also have the ABS or BRAKE warning lights on at the same time.
The first step to solving this issue is to pull the fault code from the car’s computer. Your regular OBD2 scan tool will not be able to access the ABS system, it will require a high end scan tool or a trip to your indie repair shop or the dealer. You just want them to find the fault code for you though, so it should not cost more than an hour labor.
So you’ve found that you have the fault code 88 for the pre-charge pump stored. That means one of two things: either your pre-charge ABS pump is bad, or the ABS module as a fault and needs to be repaired. In most cases, it’s the ABS module that has failed. This is because of a design flaw in which the module (computer) was placed right next to the exhaust manifolds in these BMW’s. The constant heat damages some of the electrical contacts in the circuit boards of the module over time, causing a malfunction.
To resolve this, you can have the module from your car rebuilt for around $100 plus shipping charges both ways. The downside to this is that the rebuilders cannot 100% guarantee that they will be able to repair the fault, but it’s worth a shot in my opinion. Alternatively, you can purchase a brand new Bosch ABS module here, which will definitely resolve the problem with a failed module. The downside with a new unit is the higher cost, and additionally, it will need to be coded to your car by the dealer which may cost an additional hour labor of expense.
Here’s a video I uploaded discussing the code 88 problem, along with instructions to remove and install the module from the car (2001 E39 530i).