This guide explains how to repair the 12V lithium battery on Porsche Cayenne, Lamborghini Urus, and Audi Q8 vehicles using the Xhorse Multi Prog programmer. The Multi Prog includes built-in repair algorithms that can reset and restore battery modules.
Common Fault
- DTC P1D6C00 – 12V Lithium Battery Diagnostic System Monitoring Fault
This error typically appears after a critical battery discharge. When the battery voltage drops too low, the BMS (Battery Management System) activates protection mode.
There are two ways to fix this issue:
- Replace the battery with a new one.
- Remove the protection by editing the DFLASH data in the BMS module.
Accessing the Battery
- The 12V lithium battery is located under the front right passenger’s footwell.
- Remove and place the battery on a workbench.
- The BMS board sits under the top battery cover, which is glued in place. Removing it requires some effort:
- First, remove the side cover.
- Unscrew the two battery terminals.
- Carefully detach the glued top cover to expose the BMS board.
Repair Process with Multi Prog
Although other programmers can also be used, this guide shows the process with Xhorse Multi Prog.
Pinout Reference
Target MCU: SPC5644B-ON32E (inside Porsche 12V battery module).
Steps
- Read and back up the DFLASH data.
- Use Multi Prog’s built-in function → Click “Renew and Repair.”
- Write the corrected file back to the module.
- Important: Fully charge the battery before reconnecting it to the vehicle. If the battery is not charged, the BMS may re-trigger protection.
More repair cases for Porsche engines,please refer to:Porsche Trouble Repair