Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Engine control module (ECM)
The engine control module (ECM) (4/46) controls the ignition system in the vehicle and controls activation of the starter motor via the starter motor relay (applicable to B8444S only). The engine control module (ECM) also grants permission to the central electronic module (CEM), indicating whether the fuel pump is permitted to run when ignition is attempted. These functions are activated once an approved check of the ignition key has been carried out and an identity check has been carried out between the engine control module (ECM) and the central electronic module (CEM) and the result approved.
In order for the engine control module (ECM) to work in the immobilizer system, the control module must be programmed with codes. This takes place for the first time during assembly in the factory, and subsequently takes place in the event the control module is replaced (when downloading software).
For further information, see VIDA Design and Function, engine control module (ECM).
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
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