02/08/2026 9:13 am
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Automotive Q&A
Programming support supply: what do you log before starting a module update?
Review the evidence, add a focused answer, and distinguish confirmed measurements from assumptions.
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We are building a pre-programming checklist after seeing vehicle voltage dip when cooling fans woke up during a long update. The support unit can operate in regulated supply mode and display voltage and current, but technicians have been recording only that a charger was connected.
What values and conditions should be captured before pressing Start? I am thinking battery test result, target supply voltage, available current, disabled loads, network scan and laptop power, but I do not want to publish one voltage that is wrong for another manufacturer.
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24/08/2026 10:04 am
Use the programming procedure for the exact vehicle to set the required voltage range and minimum current capacity. A regulated programming supply is not the same as a conventional charger, and modes that pulse or desulfate can be unsuitable. Record the battery assessment, supply model and mode, set point, voltage at the battery, initial current, and the highest observed current before and during the update.
Also record the pre-scan, module part and software identifiers, network or interface connection, laptop AC power and loads disabled as directed. Do not open doors, operate accessories or disconnect the interface unless the procedure requests it. If the supply cannot hold the specified range under load, correct that before programming.
Topic starter
25/08/2026 7:46 am
The revised checklist now pulls the voltage range from the job-specific procedure and requires an actual battery-terminal reading, not just the supply display. On the next update, the log caught a 0.35 V loss in an extension lead before programming began. Replacing that lead kept the vehicle inside the specified range throughout the session.