hand shake reset

[jaykay]

With the battery out for winter (wimper...sniffle), is it worth while to perform a hand shake reset of the ECU while the opportunity is there? Is there anything adverse to having the pos. and negative leads linked together all winter???

[Jake Raby]

Thats not a hand over, its a hard reset, big difference.

[JayG]

Jake, what is the difference between the two?

[Slate 01]

Hand job?

[Jake Raby]

A hand over is done electronically, it requires a scan tool thats properly equipped for the task, like an Autologic.

A "hard reset" is done by removing the battery leads and connecting them together to drain all the energy from the DME and various capacitors throughout the car.

[jaykay]

Okay pardon the incorrect terminology....is this hard reset of value as far as establishing a fresh learning cycle where intake and exhaust modifications that have been made along the way can be fully and correctly accommodated by the ECU?

[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