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Sometimes it’s the Simplest Solution

by Chad Morehead

Check out his blog at http://www.eatsleeptinker.com/

You’d have thought I’d learned my lesson with the brake debacle on the M Coupe.  A short recap; a long drawn out brake issue turned out to be simple deformed bleed screws.  The take-away; it’s often the simplest of solutions causing your problem.  So, before you start rebuilding the top-end of your S52 for excessive valve train noise, maybe you should check the oil level.

A similar difficulty presented itself recently on the ’98 M3.  I had been experiencing some soft initial brake pedal throw, not too dissimilar to what I was feeling on the ’02 M Coupe.  I had done the traditional bleeding methods.  You know; pressing the brake pedal, opening the bleeders, repeat.  The car would stop just find, witness its action at Road Atlanta and once again for good measure.

The problem was a soft initial feel, which made it a bit difficult to be completely smooth in the braking zones.  At least that was the excuse I went with when my instructor made note of my middle pedal jabs.

So once home again, I went to work on the usual suspects, namely the ABS system and its labyrinth of places where air might find itself trapped.  There are multiple DIYs out there that tell you if you simply bridge this relay plug to that one, it’ll actuate the ABS pump, and all will be well.  That’s partially true, yes you can force the ABS pump into running with a short length of wire, but that doesn’t do anything for the valves within the manifold.  So out comes the ancient laptop with DIS installed.

Laptop DIS & Charger

Now I’ve done this before on the M Coupe, while slow (thanks to the software) it does work as advertised.  I assumed the same procedure could be accomplished on my ’98 M Coupe.  Unfortunately I didn’t account for the changes in BMW‘s software/hardware architecture over the years.

I hooked up my 20-pin to USB plug as I had on the ’02 M Coupe, fired up DIS in the same manner, then started playing the usual find the proper option in a haystack.  Unfortunately I couldn’t seem to access any of the familiar options for the DSC/ABS modules as I had on the E368.  Instead I was greeted with this:

EWS Fault in DIS

Ah… the dreaded EWS, BMW‘s pain in the butt anti-theft device.  These days these systems are very common place, you’re probably familiar with the microchip RFIDs found inside keys, which are programmed to your car.  BMW has been using these systems for a long time, and they are often the bane of a modder’s existence.

Not being a very BMW computer savvy fellow, I assumed my EWS had somehow fallen out of alignment with the engine’s DME (ECU.)  I attempted a realignment, but was met with more warnings from DIS that my EWS was not playing nice.

That’s when I hit the interwebs and reached out to the seller who I had purchased my DIS software and 20-pin diagnostic cable from.  That’s where I learned that after 1998, BMW started using a different system for communication among the various modules that control all the diverse functions of the car.  I had a cable and software designed of the later cars… just my luck.

I found a few knowledgeable folks on Bimmerforums who pointed me to user rv8flyboy and his website, Interfaces 4 Beemers.  He makes (or offers a kit for you to make) a very nice ADS/OBD 20-pin cable.  This cable has diagnostic LEDs on it to help show you different faults and the status of the connection.  It also has a little toggle switch, which allows for changing from OBD (98<) or ADS connections, allowing it to be used on either my E36 or my E368 M Coupe.  The same switch also allows for resetting of oil change / service interval.

Even better is that the cable comes with a DVD copy of DIS/TIS and easy to follow instructions.  The catch; you must have a PC with a real serial port, a USB to serial adapter will not work.  You must also have a working copy of VMware (virtual machine) installed.  Fortunately I had purchased a cheap used laptop off of eBay when I first started messing around with the BMW software.  I also had a running copy of VMware, so the install went very smoothly.

I went back to the car, to rectify the EWS issue I was experiencing previously.  This time the DIS software actually identified the car properly and appeared to communicating as designed, but once I tried to align the EWS I was met with similar warnings and stoppage.

EWS Alignment
Could my keys have gone bad?  Possibly the EWS head unit itself?  Something was amiss and it was frustrating as hell.  I thought to myself, “what could cause an EWS to suddenly not work?”  Why not check the fuse?  I popped the lid to the relay/fuse box, scanning the fuse location sticker for anything that could be related.

Sure enough, the first fuse I got to, a 5A was blown!  I popped in a spare, tried to crank the engine and it turned over and started!  All this effort and a silly fuse was holding me up.  Yet another lesson that seems to be hard to learn; always check the simple solutions first.

EWS Fuse

So what about my brakes?  You’ll have to wait for another post on that.

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