Porsche 996 TT, Repair Manual

Page: 252 / 2099

Protection against overvoltage
To protect electronic control units from overvoltage during electric arc welding, the following work
regulations must be observed:
When welding work is extensive, the electronic control units must be removed. Ensure that there are
no electrically insulated parts between the ground connection and the welding point. •
Remove clamp from negative terminal of battery and cover negative terminal of battery. •
Connect the ground connection of the electric arc welding equipment as near as possible to the
welding point on the part to be welded. •
Do not touch electronic control units or electric cables with the ground connection or the welding
electrode. •
Replacing control modules
The replacement of electronic control modules after an accident is necessary if at least one of the following
conditions is met:
The housing is noticeably deformed or damaged. •
The supporting surface or bracket is deformed (the unit shows no external damage). •
The plug connection is damaged or corroded by moisture. •
Functional checks or self−diagnosis of the unit reveals the fault "Control module faulty". •
996420, 996421, 996450, 996451, 996430, 996431, 996620, 996621, 996650, 996651, 996630, 996631,
996840, 996841
einordnung
Protection against overvoltage 189