Hi, in this video I go over a simple method that can be used to swap out an original EWS II 413 Silver label DME with an earlier EWS I 413 Maroon label DME without dealer re-coding. I still don’t know everything about the EWS system but I am learning, the information below is what I have learned so far and I am passing it on to you. Thanks
As our favorite BMW E36 gets older the chances of electrical components failing come with it. The EWS system is one of those components that will leave your car stranded if it fails and there aren’t many shops capable of dealing with it. The EWS is a cool feature but so are alarm systems. If I had to choose I would go with the alarm system as I can take it to just about anyone to have it fixed or replaced it if fails, I don’t like being at the mercy of dealerships.
For those of you that are not familiar with EWS I & II it’s an immobilizer like an alarm system that you would install on any car but without a remote control to fiddle with. This was not an option, it was standard equipment mandated by the European Insurance Company. BMW made a change to their security level starting on 1/95. They went from EWS I to EWS II, the difference is EWS I which started with 93 model years did not use a chip in the key. It worked by high and low voltage signals from the (GM) control module & (BC) board computer. When you lock your car the (GM) or (BC) will send a high signal to the DME. If the DME sees a high signal it will not permit fuel or spark. The opposite happens when the car is unlocked, the (GM) & (BC) send a low signal to the DME. To up the ante, BMW installed a starter immobilization relay starting with the 7/94 model year, this relay is more aimed at preventing starter engagement while the engine is running but it will also not allow starter engagement if it does not see the correct inputs. This relay requires input from the transmission range switch (high signal start/low signal no start) The DME looks to crank position sensor if it sees over 1200 RPM it will signal the starter immobilization relay to not engage the starter. The relay also looks for signals from the (GM) (BC) & ignition switch. So it’s possible that if you have a worn out or out of adjustment transmission range switch it could prevent the engine from starting. From what I have decipher, the starter immobilization relay will stop starter engagement and also send a high signal to the DME to prevent fuel & spark if the automatic trans switch is not in the position it should be. If you find your car won’t start it wouldn’t hurt to cycle the transmission shifter back and forth a few times to see if it cures the problem, maybe even try neutral for that matter. Starter inhibitor switches have been around for quiet sometime but less complicated then BMW’s version.
Starting on 1/95 and possibly some late 94 models BMW went to EWS II. Everything is pretty much the same except BMW again upped the ante. Cars now come with an ISN coded chip in the key, antenna ring around the ignition lock which plugs into a transmitter receiver module ( the receiver is mounted above the steering column). It also includes an EWS control module with a starter relay built into it (located behind the glove box) plus an ISN code in the DME chip. The (BC) code input to the DME is eliminated. Instead of the DME looking for a high and low signal it is now sending and receiving a specific (ISN) individual serial number code to and from the EWS control module. Also the EWS control module is looking at the key to see if its code matches as well. A further update was made beginning May? of 1997 E32 & E36 vehicles with manual transmissions which were updated to include a clutch pedal position switch. The clutch switch signal is a hall effect sensor that provides a high signal when the clutch is depressed (this signal is sent to the EWS module).
In a nut shell the antenna ring energizes the key and then the key is able to send its stored code to the EWS module. I would think, it would be best to be careful with the key, keep it away from high powered magnets and wireless chargers like the Sonic Care toothbrush charging bases.
There is a way to get around the EWS II immobilizer in the event your computer (DME) ever becomes damaged. If your 1995 BMW 3 series with EWS II 413 silver label DME fails, you cannot simply run to the wrecking yard and buy a replacement one. Whether you pick up a new computer or a used one, it will have to be realigned with the EWS module first by means of a piggyback computer like the BMW GT1; the cost is in the neighborhood of $2000 and up for one of these bad boy’s, although there are some knockoffs for half this price. This is usually done by a knowledgeable locksmith or a BMW shop/dealer. Otherwise, your engine won’t start because the replacement DME computer chip will not store the same codes that your original chip did. Your only other option in this situation is to try transferring your original ews coded chip into the replacement silver label DME in hopes it was just the mother board or injector drivers that failed and not the chip itself. Note, that owners of 96 and up model years will have to upload an EWS delete program into the DME; Shark injector software might be an option. 96 and up BMWs do have EWS II but the DME chip is not the same; although on 96 & up models you can bypass the starter relay that is built into the EWS module in the event it ever fails.
The following procedure outlined in this EWS video will bypass the dealership and save you some money in the process if you ever find yourself in the need of a replacement DME. Keep in mind that you will still need your original key to start the car with this bypass due to the EWS module’s starter inhibitor function. Once you perform the bypass, you will have a few options as to what DME configuration you can use.
1) Install a 413 Maroon label DME as a complete unit from a 92-94 E34 525i / E36 325i,is
2) Install a 413 Maroon label DME chip from a 92-94 E34 525i / E36 325i,is 413 into your 1995 E36 325i,is Silver label 413 DME.