hand shake reset

[Bigsmoothlee]

Technicians are taught to never let the battery go dead or disconnect the terminals in Network/CAN bus cars (especially Mercedes), because you can trash a control unit on the interior bus if the power is removed while its going to sleep. The terminals should be kept hot with a booster pack and jumper wires during a battery replacement.

Some computers may be "stuck on stupid" even after resetting with the scan tool, requiring a hard reset. For example, if the dashboard would be indicating a transmission malfunction, and you perform the repair and fix the codes, the light may continue to stay on even though faults are no longer stored in the transmission ECU. A hard reset corrects this.

Why are you disconnecting the battery? Why not leave a trickle charger on it?

[jaykay]

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[jaykay]

I pull the batt every winter as there is no charge source to be had in the storage location. I have tried rotating power packs plus a trickle in the past but they seemed to have just barely kept the batt. alive and led to sulphication