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    BMW's EWS Systems

    A summary of BMW's immobilizer systems 1987-1999 (covers mostly E36 applications).

    OBC Immobilizer, many 87-92 = the OBC and DME are linked. If the OBC code was entered (or the OBC relay failed) power to the DME was stopped (no ignition). Depending on your project and the level of functionality you plan to retain, the OBC and OBC relay may remain in the car and could lead to no-start problems if not wired correctly.

    EWS, E36 9/93-12/93 = links the door lock switch to the DME and OBC. If the door was locked with the key (or factory alarm) the car will not start without the doors unlocked with the factory key or entering the code into the OBC. In other words, you can’t smash the window and hot wire the car because the DME has killed the ignition and fuel systems.

    EWS-I, E36 1/94-12/94 = same as above but added a starter immobilization relay and transmission position switch.
    In either of the above systems the DME is passive. It only receives signals from sensors and modules. So the DME is not as tied into the body electronics as much as EWS-II.

    EWS-II, E36 1/95-8/96 = similar to the above but with an electronic key, EWS module (“brain”), and the DME all linked together. The same door lock logic remains. All systems for starting the engine are run through the EWS module (starter relay, starter power, fuel, ignition). The key sends a signal to the EWS module and the module asks for a matching signal from the DME. If the two signals don’t match the EWS module will not start the car. The EWS module also checks for OBC function and transmission park/neutral position.

    EWS-III, E36 9/96-8/99 = revised EWS-II system with added clutch position sensor and revised module and wiring.

    Problems with EWS-II and Engine Conversions.

    Why is EWS-II bad? This system can be a major stumbling block for a car that has an engine conversion or on a car that no longer needs the EWS-II system active. Cars that have had an engine swap, such as an E30 with an M50/S50/S52, may experience difficulty with the DME as the computer is looking for the signal from the EWS-II computer. E30s - and other models built before 12/94 - obviously do not have an EWS-II system. So we remove the code that makes the DME ask for the EWS signal.

    Racecars will not need the EWS-II system and will likely have that wiring and electronics removed from the car to save weight and increase reliability. Our software will allow the engine to be used with its original DME, thereby saving the owner labor and frustration in sourcing another DME.

    What does our EWS-delete software do? Our software is designed to disable the EWS protocol in the DME itself. It's like having an earlier non-EWS DME. For this to work properly, you cannot have any EWS-II components in the car. All of the original EWS equipment, including the ignition key, cannot be present. This is why our d-EWS chips will not work to fix a pre-existing EWS problem. Our software is strictly for using an EWS-II DME in a non-EWS car. If your EWS is experiencing problems, you may need an EWS alignment (synching all of the components together via a diagnostic computer), or you may have to replace the EWS module or key.

    Turner Motorsport EWS Delete Chip
    EWS-Delete Chip For Bosch 413 ECU with silver label. Our chip will de-activate the EWS-II code inside the DME, thereby allowing you to use the car in an engine conversion (E30 owners with M50 engines!), or on a racecar that has the EWS-II removed completely. It also has all of the benefits of the "regular" Conforti Performance Chips -- more horsepower and torque, increased rev limit (7000 rpm), top speed limiter removed, etc. In the past you would have had to track down a non-EWS computer, or worse, cut up the factory wiring. This chip saves you both time and money.
    Click here for more on our EWS-Delete chip.

    Over the years owners made changes to the specs of their cars. It was common for EWS-II modules to fail and a replacement was over $400. It became common for people to install a cheaper EWS-I DME and cut some of the EWS-II wires. Unfortunately this creates a lot of confusion on which chip and DME combination to use. On an M3 you no longer want to match chip part number to ECU part number. BMW installed a "506" ECU in the EWS-I E36 M3 and a red 413 ECU in EWS-I 325i/525i. So you must use a 506 M3 chip with the red 413 or any 506 ECU. If you have a silver 413 ECU you must use the "4131" M3 chip. It's gotten very confusing over the years but we have it figured out.

    BMW/Bosch E36 ECUs
    Model Prod. Years ECU P/N Turner Chip P/N
    non-VANOS ECUs (included for reference)
    325i, 525i 1992
    0 261 200 402
    0 261 200 403
    0 261 200 405
    325i, 525i 1993-12/1994 0 261 200 413
    (red/maroon Bosch label)
    M3 3/1994-12/1994 0 261 203 506
    (grey Bosch label)
    EWS-II (factory spec, no changes to EWS system)
    325i, 525i 12/1994-12/1995 0 261 200 413
    (silver Bosch label)
    M3 12/1994-12/1995 0 261 200 413
    (silver Bosch label)
    EWS-II with modified/cut EWS wiring
    325i, 525i 12/1994-12/1995 0 261 200 413
    (red/maroon Bosch label)
    M3 12/1994-12/1995 0 261 200 413
    (red/maroon Bosch label)
    0 261 203 506
    (grey Bosch label)