IMMO Off Service
Immobiliser fault or ECU not authorising start?
Mobile IMMO diagnostics and ECU software assessment for non-start faults, ECU swaps and key issues.
IMMO Off Service
- ✓No-start symptoms checked before advice
- ✓ECU, key and immobiliser route explained
- ✓Original ECU data backed up where readable
- ✓Mobile support across London and the North West
Immobiliser fault help when the vehicle will not start
Immobiliser problems are stressful because the vehicle can look mechanically healthy but still refuse to start. We help with ECU replacement, key authorisation faults, lost-key situations, damaged immobiliser data and track or off-road builds where IMMO-off software is appropriate.
Send your registration, ECU type if known, and what happens when you turn the key. We will confirm the likely route before you book.
When IMMO work may be needed
- No-start with immobiliser message: The ECU is not receiving or accepting start authorisation.
- Replacement ECU: Donor ECUs often need matching, cloning or immobiliser data work before the car will start.
- Lost keys or damaged modules: Key, transponder, cluster or ECU data can stop authorisation.
- Track / off-road builds: IMMO-off can simplify standalone or converted setups where appropriate.
What you get with BSG Automotive
- Initial fault and use-case assessment before software advice
- ECU, key and immobiliser symptoms reviewed
- Original ECU data backed up where readable
- Clear advice on cloning, matching or IMMO-off routes
- Mobile support across London and the North West where practical
If key programming or ECU cloning is the better route, we will say so before carrying out IMMO-off work.
Frequently Asked Questions
This is commonly required if you are installing a used ECU from another vehicle, building a track car, or if your factory immobiliser has failed.
Yes, the factory immobiliser will no longer function. We recommend installing an aftermarket alarm or physical security device.
Most IMMO off procedures take 1-3 hours depending on the vehicle make and ECU type. Some older systems can be done faster, while newer encrypted ECUs may require bench work.
We can disable the immobiliser on a wide range of vehicles including BMW, Mercedes, VW, Audi, Ford, Vauxhall, Renault, Peugeot, and many Japanese and Korean makes. Contact us with your vehicle details for confirmation.
Yes, this is one of the most common reasons for IMMO off. When fitting a replacement ECU from another vehicle, the immobiliser codes won't match. Disabling the immobiliser allows the replacement ECU to start the engine immediately.
Absolutely. Track and race cars often run stripped-down wiring looms without the original key system. IMMO off allows the engine to start with a simple ignition switch, which is standard practice in motorsport builds.
Yes. We save a backup of the original ECU software before making changes. If the original key system is still intact, the immobiliser function can be restored at any time.