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.
Back-up Functions
The PHM first tries to establish contact by means of the main antenna, then the back-up antenna. If this fails, contact is established via satellite. In this mode, only data is communicated.
The back-up functions only work when:
- the SOS or On Call button is used,
- a component is activated in the SRS system,
- the alarm is tripped.
Back-up Battery
If there is no normal power supply, the back-up battery takes over the power supply.
The battery can be replaced.
If the battery capacity falls below 30%, the driver is alerted by a message on the DIM.
Back-up Antenna
If there is no normal antenna connection, the back-up antenna takes over the functions.
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:
- • 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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