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.
Start Control Module (SCU)
The start control module (SCU) (3/1) is in the dashboard beside the steering wheel. The start control module (SCU) contains a cylinder for the key, an antenna ring and four contact breakers. There is one contact breaker for each of the three key positions (I-III) and one to indicate that the key is in the ignition switch.
The contact breaker for key in is designated Key-in contact breaker.Β The key-in contact breaker closes when the key is inserted in the ignition and indicates to the central electronic module (CEM) that the car is about to be started.
The antenna ring is activated by the central electronic module (CEM) when the signal from the key-in contact breaker has been received. The antenna ring allows the central electronic module (CEM) to communicate with the transponder in the ignition key.
The key does not need to be in the ignition switch if there is a keyless vehicle module (KVM) in the vehicle. There is a starter button instead. The starter button must be pressed in before it can be turned from position 0 to I. This activates the key-in switch. The identity of the key is then checked via the antennas in the passenger compartment instead. These antennas are connected to the keyless vehicle module (KVM).
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
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