BMW CAS3 (Car Access System) Immobiliser ECU Repairs
Are you having ignition problems? Does your BMW vehicle not start? If so, this could be due to an issue with your CAS immobiliser module.
The CAS immobiliser module (transponder box) serves as an antitheft alarm system and enables the start of BMW vehicles. Within each vehicle key there is an integrated transponder chip, and a coil ring which is fitted around the ignition lock. The transponder chip is powered by this coil from the CAS module, meaning that no battery is necessary within the key. When your key is inserted in to the ignition, the transponder in the key is powered via the loop antenna, and key data is sent to the CAS control module. If the key data is correct, an enable signal is then sent to the starter and the CAS module then sends the random code to the Engine Control Module (DME / DDE) where the random code is checked against the saved random code. Only if they match, is the fuel injection released allowing the car to start.
Common faults associated with the BMW CAS3 Immobiliser module
As mentioned above, some of the issues that you may encounter if you have a problem with your BMW CAS3 module are:
- Immobiliser Fault Codes
- No Communication with CAS3 Module
- Vehicle Won’t Start
- Key Not Recognised
Most workshops will advise to replace the immobiliser module because they are unable to repair it. It’s not possible to replace them with a second hand part because the unit will be locked to the vehicle it came from and unless you’re buying a complete immobiliser kit, you will require a new CAS3 module and the unit must be programmed.
CAS3 Immobiliser Module Repairs – By Sinspeed
Here at Sinspeed, we’re able to fully test and repair the BMW CAS3 immobiliser module using new genuine OEM components and uprated components where possible to ensure each and every repaired BMW CAS3 ECU is rebuilt to meet & exceed OE specifications. All remanufactured units are returned with a Lifetime warranty and will not require programming.
If you have a BMW CAS3 Immobiliser fault, give us a call today on 0203 815 9441.

Ajaz is a seasoned automotive electronics engineer with deep expertise in remanufacturing vehicle electronics. He has developed skills in all areas of the automotive field, from rebuilding hydraulic steering components, and mechanical gearboxes and reworking intricate vehicle electronics. Ajaz also acquired Bodyteq, a London-based vehicle bodyshop where he has developed extensive knowledge in automotive refinishing.
Alongside his automotive career, Ajaz has built a career in the IT industry, gaining accredited certification as an AWS Certified Cloud Practitioner, Cloud Architect, and Search Engine Optimisation (SEO) specialist.
Hi. My BMW e91 2005 has problem after upgrade cas. Upgrade was unsuccessful. Engine start but opening closing won’t work, on speedo flashing all warning. Yellow steering wheel flashing with paddle Lock. NNow there is no communication with car. I need update cas asap. Thnx
Hi Slav
Thanks for the enquiry,
We’ve sent you an email with some detailed information on this type of problem.
Kind Regards
Jason
SINSPEED
Friend.
I need to repair my BMW 530i e60/2007 CAS 3 burned you have to help me?
Await response.
Hi Espinoza
Thanks for the enquiry,
We have sent you an email with full pricing and information to remanufacture the CAS3 module.
Kind Regards
Jason
SINSPEED
Hi could give me a price to repair and cas module on 2004 e61 2.5i
Hi Nik
Thanks for the enquiry,
We can definitely test and repair the CAS module and I’ve sent you an email with full pricing and information.
Kind Regards
Jason
SINSPEED
Please can you send me a price List for BMW cas 3 Module repair / Reprogramming. Many thanks for your help. Julian.
Hi Julian
Thanks for the enquiry,
We’ve sent you an email with pricing for testing and repairing the CAS 3 Module.
Kind Regards
Jason
SINSPEED
Hi could give me a price to repair/replace cas module on BMW 2004 530i?
Hi Elliot
Thanks for the enquiry,
We’ve sent you an email with full information and pricing.
Kind Regards
Jason
SINSPEED
Hello could you give me a price fir repair of CAS unit for 2011 318d please. Thanks. Lee
Hi Lee
Thanks for the enquiry,
We have sent you an email with full information and pricing.
Kind Regards
Jason
SINSPEED
My bmw 1 series 13 plate has A Main car access intetnal failure wil this b covered under warranty or not coz my car give me no warning wats so ever. It’s taken bmw 3 days to find this fault on my car. Wen i think The bmw warranity shud cover this the cars only Done 51000
Hi Gemma
Thanks for the enquiry,
If your vehicle is out of warranty with no extended cover then it will very much be at the dealers discretion whether or not to cover you for this fault. However, you can contact BMW customer service direct and raise your concerns with them and they may grant a goodwill repair.
I have sent you an email with full information and pricing for our services if all else fails.
Kind Regards
Jason
SINSPEED
Hi i have A bmw 530d e60 2004 i would like a price on repair of my cas module
Hi Hussain
Thanks for the enquiry,
We have seen many CAS modules from the BMW 530D E60 model and successfully repaired them. I have sent you an email with full information and pricing.
Kind Regards
Jason
SINSPEED
I was using sss v32 to re code aux line but the software said i need to do a up date on some Ecus .a plan was adviss .i run the up dates and it started on cas and then stop i ran It agan but no luck i have No dash lights or power on key .and No remote looking can you help me
Hi David
Thanks for the enquiry,
We have sent you an email with full information and pricing.
Kind Regards
Jason
SINSPEED
Hi
I have a 2007 118d which seems like a cas problem.
What do u charge
Thanks
Hi Mark
Thanks for the enquiry,
We have sent you an email with full information and pricing.
Kind Regards
Jason
SINSPEED