Disconnecting 48 V Vehicle Electrical System

Information 

The PIWIS Tester  instructions take precedence since the description may be different with later Tester releases.

The procedure described here has been structured in general terms. Different text or additional information may appear on the PIWIS Tester. 

Connect the Tester to the vehicle and start it. Switch on ignition.

Select the vehicle type if necessary.

Select the Gateway  control unit in the overview.  Press F12 to continue. Is a "Vehicle Analysis Log (VAL)" to be created? Press F11 to continue.

Select Maintenance/repairs.  Press F12 to continue.

Deactivate 48-volt vehicle electrical system  must be selected. Press F12 to continue.

Read the information and instructions displayed on the Tester. Press F8 to start.

Perform procedure according to menu guidance. Read the warnings displayed on the Tester. Press F8 to continue.

Go back to the overview. Press F11 to continue.

Switch off ignition, move the hand-held transmitter out of the range of the vehicle and disconnect the Tester from the vehicle.

NOTIFICATION 

Voltage drop 

• Irreparable damage to control unit 
• Damage to control unit 
• Fault entries in the control unit 
• Control unit programming/coding is aborted 
• Malfunctions in the control unit, even during programming/coding 

  → Switch off ignition before disconnecting the control unit.

  → Make sure that the power supply is not interrupted during programming/coding.

  → Connect the battery charger with at least>current 90 A  to the vehicle battery.

Information 

Switch off all electrical loads and move remote control (hand-held transmitter) out of range.

• Do not disconnect the battery while the engine is running. 
• Disconnect and re-connect battery with extreme caution. 

Disconnect 12-volt vehicle electrical system battery.

> 270619 REMOVING AND INSTALLING VEHICLE ELECTRICAL SYSTEM BATTERY - on "Removing"

Insulate terminal clamps, e.g. wrap insulating tape around terminal clamps.

The following 48-volt system components can now be removed and installed or replaced:

> 407719 REMOVING AND INSTALLING FRONT STABILIZER (PDCC)

> 429019 REMOVING AND INSTALLING STABILIZER (PDCC)

> 270719 REMOVING AND INSTALLING 48-VOLT AUXILIARY BATTERY

> Refer to the appropriate service information.

> 270319 REMOVING AND INSTALLING 48-VOLT VOLTAGE CONVERTER

> Refer to the appropriate service information.

> 978919 REMOVING AND INSTALLING 48-VOLT CURRENT DISTRIBUTOR