Immo OFF Stuttgart
If the key is not recognised, start authorisation is missing or the vehicle will not start after a control unit replacement, we identify the cause and recommend the appropriate route: repair, adaptation, coding, ECU cloning or — only in an authorised, suitable individual case — Immo OFF.
MG AutoTech distinguishes key, voltage, communication, ECU and immobiliser faults. This prevents Immo OFF from becoming a blanket answer to every starting problem.
Before work begins
The battery, key, aerial, power supply, wiring, ECU and vehicle communication can cause similar symptoms.
Repair, adaptation, coding and ECU cloning are assessed as alternatives before Immo OFF is considered.
Authority to act in relation to the vehicle, its configuration, intended use and approval status are part of the individual assessment.
01 / Direct answer
Immo OFF means a modification that deactivates the immobiliser function relevant to start authorisation in the affected control unit network. It is not a general repair or a substitute for diagnosing an unknown starting problem.
We first check whether the cause lies with the key, power supply, aerial, start authorisation, control unit communication, data assignment or a faulty component. Repair, adaptation, coding, ECU cloning or a suitable replacement may be the better technical approach. An Immo OFF enquiry is assessed only after authority, technical suitability and intended use have been checked.
02 / Diagnostic overview
Similar symptoms can have different causes. That is why we distinguish what you observe from what may be causing it.
03 / Technical assessment
Every job is assessed using the vehicle’s condition, control-unit data and fault history—not just the model name.
Common searches include “immobiliser active”, “key not recognised”, “start authorisation missing”, “engine cranks but will not start” and “car will not start after ECU replacement”. An engine that briefly starts and then stops is also often attributed to the immobiliser too quickly.
None of these symptoms alone proves an immobiliser fault. A weak battery, key or aerial problem, missing power supply, wiring faults, engine management, fuel supply or communication within the vehicle network can produce similar behaviour.
Modern start authorisation is not just a single function in the engine ECU. Depending on the vehicle, the key, receiver or aerial, access and body control unit, ignition or starting system and engine ECU exchange information across the vehicle network.
That is why a fault code is not assessed in isolation. What matters is which control unit records it, whether the key is recognised, how the ignition and starter behave and whether the modules involved communicate plausibly.
A used or new engine ECU is not automatically assigned to the vehicle when fitted. Hardware, software version and relevant vehicle data must match the system. A vehicle that will not start after an ECU replacement therefore first needs identification and an adaptation assessment.
If the original data is still readable and a compatible replacement is available, ECU cloning may be an option. A data or software problem may be better addressed through programming or recovery. Immo OFF is not offered as a shortcut around these checks.
The vehicle and job context must be understandable, and the authority to act in relation to the vehicle must be credible. The cause of the fault, vehicle configuration and intended use must also be sufficiently clear to allow a responsible technical decision.
Do not include security-sensitive documents in your initial enquiry. Send vehicle details, fault symptoms, complete diagnostic information and intended use. Any evidence needed to accept a possible job will then be agreed securely for the individual case.
Where a key, power supply, communication or control unit fault can be repaired, restoring the intended system is often more appropriate. Deactivation does not repair a faulty battery, damaged wire or incompatible software version.
Section 38a of Germany’s StVZO requires passenger cars to have an immobiliser. There is therefore no blanket approval for Immo OFF on public roads; vehicle type, specification, use, operating permit and inspection requirements must be clarified specifically before a modification.
04 / Workshop process
Record vehicle details, starting behaviour, job context and intended use.
Assess fault codes, key status, power supply and the control units involved.
Assess repair, adaptation, coding, ECU cloning and replacement as alternatives.
Clarify authority to act and technical and legal suitability for the individual case.
Carry out any agreed work only after clear approval and without disclosing the procedure.
Then check communication, fault memory and the agreed vehicle function.
05 / Preparing your enquiry
The more complete the initial information, the more precisely we can identify the right checks and next steps.
Before you place an order
Immobilisers are safeguards against unauthorised use. An Immo OFF enquiry is therefore handled only within an understandable, authorised job context and without publishing security-sensitive procedures.
Section 38a of Germany’s StVZO requires passenger cars to have an immobiliser. A modification may also have implications under Section 19 StVZO. Its specific permissibility depends on vehicle type, specification, use and supporting evidence; MG AutoTech gives no general assurance of TÜV acceptance or road approval.
06 / Frequently asked questions
No. The battery, power supply, starter, key, aerial, wiring, fuel system, engine management and vehicle communication can cause similar symptoms.
It may be related to missing start authorisation, but also to fuel supply, ignition, sensors, engine management or voltage. Fault codes and live status data must be assessed together.
At least one system involved reports that the expected authorisation or communication for starting is incomplete. Diagnosis is needed to identify the component or assignment responsible.
Depending on hardware, software version, data access and vehicle configuration, cloning, programming or adaptation can be assessed. A general commitment based only on the vehicle model is not possible.
Before any possible work, authority to act in relation to the vehicle must be credibly demonstrated. The specific documents and secure verification process are agreed case by case after the technical initial assessment; identity documents must not be sent through the general web enquiry.
Section 38a of Germany’s StVZO requires passenger cars to have an immobiliser. Blanket approval for Immo OFF on public roads is therefore not possible. Permissibility, operating permit and approval status must be clarified for the vehicle and intended use before a modification.
No. The code must be assessed together with the reporting control unit, key status, starting behaviour, power supply and vehicle communication.
Relevant starting points
Next step / MG–ECU / 03
Next step
Send your vehicle details and describe the issue or your goal. MG AutoTech assesses the technical options before recommending an appointment or further work.