800gs EWS

herbie999

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Hi all new on here 2008 BMW f800 gs
I have got the dreaded EWS code on the dash and now won’t start it cut out while riding with no warning whatsoever
It has been of the road for about 5 years but was running fine
Iv done a little research and seems to be pointing at the Ecu
Is this just a case of getting a second hand one with keys and swapping out
Has anyone done this ?
Also do the numbers on the Ecu have to match exactly as not found anything with the exact numbers or just similar and can you use BMW f800 s or has it got to be a Gs
Any help would be much appreciated
 
Afaik,

EWS is a failure of the ring antenna / signal / power round the lock barrel

Once the bike is running, the EWS antenna is closed out of the system
 
My experience of the EWS warning and a dead bike was as above. The ring antenna around the ignition barrel.
A very cheap part compared to an ECU.
 
I have changed the ring antenna but still nothing
Also no neutral light and low beam light on when key is turned
 
When I changed the ring antenna the ignition barrel seemed reluctant due to the accumulation of dirt being disturbed.

A good flushing with a suitable liquid did the job. WD40 I think.
 
I have changed the ring antenna but still nothing
Also no neutral light and low beam light on when key is turned
In that case, you have some more diagnosing to do. I had exactly the same problem on my '07 1200, which turned out to be a fault in the permanent live 12v wire to the ECU. Simple fix by wiring it direct to the battery.
You need to check the permanent live, the switched live and continuity of the 4 wires from the ring antenna to the ECU. Other on here have reported your symptoms which turned out to be a broken wire around the headstock.

Here is a copy and paste from the thread I found, written by someone cleverer than me at auto electrics, and which is about a faulty F800, which led me diagnose the fault. Best of luck!

Disclaimer: I am no expert. Take the below as exactly what it is: ramblings of a random bloke on t'Internet. It is a pointer to start googling and investigating further. My motive is only to offer info to try to offer some info to help fellow bikers.

So, that out of the way, EWS (Electronische Wegfahrsperre) can come up as an error for many reasons, but thinking logically... Simplistically speaking, the bike key holds a passive "chip" inside it with a code, it goes in to the antenna which [given that the electronic power is there] agitates the key chip and "reads" the code off the chip, sends it to the ECU, which, then, compares it with the stored value and allows the bike to be started if they match. So, components involved : Key, antenna, some wiring, ECU [and indirectly the battery].

So... if the low-beam stays on, there is no whirring from the idle-actuator, no pulse on the fuel pump and no gear indication on the LCD... those symptoms are the same as it the ECU [BMSK-P] was actually completely disconnected. It would then not be illogical to think that the ECU is not booting up. If you can use a multimeter, you can do some basic tests. Head to the smaller of the two ECU connectors under the seat. Disconnect it and do some continuity/voltage tests. If I remember the pinouts correctly (let me know if they are not as expected and I will double-check/correct the post for future reads):

1) Firstly, check that you are getting power to the ECU. You should have the battery voltage [~12V] across pin-3 (-) and Pin-6 (+). (Pin-34 should be the switched +12V [i.e. ON when IGN ON]). The belts-and-braces method is to wire a consumer (like a small automotive (12V) light-bulb) to those to check for the solid current under load.

2) Check you are getting good earth too.(continuity to the frame/engine/battery(=) @ pin 3) may as well check the brown cable going from the battery(-) to the engine on the left side, near the starter.

3) Since you are already at the ECU connector, If you have disconnected the ring-antenna, you may as well check the continuity to the ring antenna; Although that is unlikely to be the problem at this stage, If the theory is sound and the ECU is not booting up at all.
Pins 1234 @ ring antenna should have continuity to pins 8,43,55,57 on the smaller ECU connector, respectively. Numbers are cast into the connector but are very small. Top-tip: Use your phone camera for magnifying if your eyesight fails you in this endeavour.
:)

Ensure that there is no continuity between the ring-antenna connector pins too (in case of cables chafing against eachother)
[You may need some pins to insert into the connectors if your multimeter probes are too fat.]

If all of this is as expected, chances are the ECU has a problem and is not booting up...


Hope that helps someone...
 
In that case, you have some more diagnosing to do. I had exactly the same problem on my '07 1200, which turned out to be a fault in the permanent live 12v wire to the ECU. Simple fix by wiring it direct to the battery.
You need to check the permanent live, the switched live and continuity of the 4 wires from the ring antenna to the ECU. Other on here have reported your symptoms which turned out to be a broken wire around the headstock.

Here is a copy and paste from the thread I found, written by someone cleverer than me at auto electrics, and which is about a faulty F800, which led me diagnose the fault. Best of luck!

Disclaimer: I am no expert. Take the below as exactly what it is: ramblings of a random bloke on t'Internet. It is a pointer to start googling and investigating further. My motive is only to offer info to try to offer some info to help fellow bikers.

So, that out of the way, EWS (Electronische Wegfahrsperre) can come up as an error for many reasons, but thinking logically... Simplistically speaking, the bike key holds a passive "chip" inside it with a code, it goes in to the antenna which [given that the electronic power is there] agitates the key chip and "reads" the code off the chip, sends it to the ECU, which, then, compares it with the stored value and allows the bike to be started if they match. So, components involved : Key, antenna, some wiring, ECU [and indirectly the battery].

So... if the low-beam stays on, there is no whirring from the idle-actuator, no pulse on the fuel pump and no gear indication on the LCD... those symptoms are the same as it the ECU [BMSK-P] was actually completely disconnected. It would then not be illogical to think that the ECU is not booting up. If you can use a multimeter, you can do some basic tests. Head to the smaller of the two ECU connectors under the seat. Disconnect it and do some continuity/voltage tests. If I remember the pinouts correctly (let me know if they are not as expected and I will double-check/correct the post for future reads):

1) Firstly, check that you are getting power to the ECU. You should have the battery voltage [~12V] across pin-3 (-) and Pin-6 (+). (Pin-34 should be the switched +12V [i.e. ON when IGN ON]). The belts-and-braces method is to wire a consumer (like a small automotive (12V) light-bulb) to those to check for the solid current under load.

2) Check you are getting good earth too.(continuity to the frame/engine/battery(=) @ pin 3) may as well check the brown cable going from the battery(-) to the engine on the left side, near the starter.

3) Since you are already at the ECU connector, If you have disconnected the ring-antenna, you may as well check the continuity to the ring antenna; Although that is unlikely to be the problem at this stage, If the theory is sound and the ECU is not booting up at all.
Pins 1234 @ ring antenna should have continuity to pins 8,43,55,57 on the smaller ECU connector, respectively. Numbers are cast into the connector but are very small. Top-tip: Use your phone camera for magnifying if your eyesight fails you in this endeavour.
:)

Ensure that there is no continuity between the ring-antenna connector pins too (in case of cables chafing against eachother)
[You may need some pins to insert into the connectors if your multimeter probes are too fat.]

If all of this is as expected, chances are the ECU has a problem and is not booting up...


Hope that helps someone...
I have done the checks with wiring and all seems fine so am assuming it is the Ecu
Dose anyone know if it has to be off a ha or is the st the same and could use one of that as struggling to find a second hand one with keys ?
Could really do with a donor bike to check if it is the ecu to make sure before splashing out on one
Anyone on here kind enough to do a bit of swapping would be fantastic but understand if not
Thanks for the help
 
I have done the checks with wiring and all seems fine so am assuming it is the Ecu
Dose anyone know if it has to be off a ha or is the st the same and could use one of that as struggling to find a second hand one with keys ?
Could really do with a donor bike to check if it is the ecu to make sure before splashing out on one
Anyone on here kind enough to do a bit of swapping would be fantastic but understand if not
Thanks for the help
Sorry to hear that didn't work.
There are companies out there who will test the ECU and potentially fix it.
www.ecu.de list the BMW ECU on their website as one they work on. Unfortunately they apparently no longer deal with the UK due to Brexit issues, but if you know someone resident within the bloc who could forward it on.....
Best of luck.
 
Hi, my problem is only when the bike has been started and run for approx 10 seconds, the amber light and EWS light comes on and the rev counter sometime stops working. This happens once or twice in the first few minutes with the bike running, then its perfect for the rest of the day.
So far the bike has never stopped running, but I guess a breakdown is not far away.
I think my 1st job is to replace the old antenna ring and see how it goes.
With genuine antenna ring fit does it need to go to BMW to be coded or will the key I'm using work ok without?
Thanks in Advance.
Neil
 


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