As the thread has turned towards the critical aspect of battery voltage during reprogramming, here's my 2¢...
Thanks to several mandated ECU updates on the brand I work on daily (Brand X), I have gained even more experience in this aspect! By the way, nationally, Brand X is having a problem with bricked ECUs due mostly to poor reprogramming technique.
The charging station we are commanded to use by Brand X is a multi-thousand dollar monster with built-in battery diagnostics, low output "ripple" and fine control over voltage. It performs a battery test before committing to "Power Supply" mode. If a car with a bad battery is presented, we use a temporary donor battery for reprogramming.
If you intend to replicate this on the cheap:
Typically, the power supply mode used for reprogramming requires an initial current of 20-40 amps to maintain 13.6 volts, quickly dropping to around 8 -15A for a vehicle with the Key ON, headlights and all accessories OFF, and in some cases and as specified, certain systems like the cooling fans or anti-lock brakes unplugged.
The first step : Get the battery tested, even if it is a Dealership-supplied battery less than a week old. BTW, the expensive dealership battery usually has the highest quality for a given car.... auto manufacturers HATE the poor reputation the car receives because of a poor quality battery, so this is something they don't skimp on.
The second step: Make sure that the battery is fully charged and is not cold or excessively hot. Cold batteries drop power quickly, so the car should be at room temperature preferably overnight and on a trickle charger.
The third step: Obtain a battery charger that can deliver 10-15A on a continuous basis. This will initially be too low, but should avoid excessive voltage or ripple. Also, it's best to have a voltmeter on hand. The high-quality battery mentioned above will absorb most ripple and voltage fluctuations. This is where the el-cheapo battery will brick your ecu!
The fourth step: Turn off all accessories, particularly the climate control system and Daytime Running Lights. If Daytime running lights can not be turned off, additional battery charger power must be supplied to maintain voltage at around 13v. If the reprogramming instructions advise disconnecting systems like cooling fans, do so.
The fifth step: Connect the battery charger, Turn the Ignition ON with engine not running , connect up your DICE, start up VIDA. After the several minutes this will take, check the battery voltage. VIDA conveniently displays this on the screen before reprogramming begins. Adjust the charger to obtain 13 - 14.5 volts.
Begin your reprogramming routine as described in my earlier post. Above all DON'T PANIC! The car may appear to "go dead" and VIDA may appear to freeze. This is normal... do NOT unplug any cables, do NOT use CRTL+ALT+DEL, and do NOT click on anything trying to find out what is wrong.
It is most important that no other programs are running on the computer, that its own battery does not die and that Windows Update does not start.
The reprogramming will usually succeed even if the battery voltage drops to 12V or slightly lower, but the chances of success is best at around 13V. Voltage climbing above 15V should immediately be reduced.
After a seeming eternity, VIDA will inform you that the reprogramming process is complete or has failed. If the car has appeared to have "Gone dead" it will now spring back to life suddenly.
Having Completed, clear any fault codes, re-assemble the car and Happy Motoring.
Having Failed.... Well, that can get very tricky. Possibly a second attempt can succeed, possibly an expensive tow and a gigantically more expensive extended visit at a Volvo dealership will be needed.
But that is the risk of software updates! As someone posted regarding updates, "If it ain't broke, don't fix it...."
Good Luck and Welcome to my World....
