Xhorse Multi Prog Clone BMW CAS3+ Module on Bench

BMW CAS (Car Access System) modules are critical components that control vehicle immobilization, ignition, and key functions. When these modules fail, they can cause frustrating issues like intermittent starting problems, clicking relays, and battery drain. This guide walks through the professional process of cloning a BMW CAS3+ module using the Xhorse Multi Prog programmer, based on a detailed demonstration of the procedure.

 

Understanding the CAS3+ Module

The CAS3+ module can be identified by its hardware version C4. These modules are found in various BMW models including the E90 3-series, Mini vehicles, and E70 X5 models. Common failure symptoms include:

• Intermittent ignition switching
• Flickering LED indicators when keys are inserted
• Clicking relays from the dashboard area
• Inability to switch on the ignition
• Partial electrical failures
• Battery drain issues

Before beginning any cloning procedure, it’s essential to diagnose the module properly to confirm hardware failure rather than software issues.

 

Diagnostic Testing
Bench Testing Setup

The first step involves setting up a proper testing environment:

• Connect the CAS module to a bench power supply at 14 volts
• Install the ignition key in the slot
• Monitor LED indicators for proper behavior
• Use diagnostic equipment/scanner with appropriate dongle
• Identifying Problems

When testing a faulty CAS module, you may observe:

• Flickering LEDs during key insertion
• Unpredictable ignition switching
• Terminal 15 output irregularities
• CAS control unit fault codes
• Oscillating voltages when testing terminals

Using diagnostic tools, you can read fault codes and data streams to confirm hardware damage. Terminal 15 outputs (one, two, and three) showing irregular behavior typically indicate internal hardware failure rather than software corruption.

Required Tools and Equipment

For this cloning procedure, you’ll need:

• Xhorse MultiProg programmer
• Xhorse XDNP11 CAS3 adapter board
• Power supply
• USB cable
• Appropriate connection cables
• Small screwdrivers for board preparation
• Microscope or magnifying glass (recommended)
• Cleaning tools for contact points

 

The Cloning Process
Step 1: Board Preparation

Opening the CAS module requires careful attention:

Mark the original and donor modules clearly to avoid confusion

Carefully open the CAS module housing

Access the circuit board

Identify the processor type (typically OL15Y or 2K79X)

Step 2: Cleaning Contact Points

The CAS board is coated with protective lacquer that must be removed from contact points:

Locate the holes needed for the adapter bracket

Clean the pads on the large capacitor

Expose all necessary connection points

Use a microscope to ensure thorough cleaning

Be extremely careful not to damage nearby traces or components

Critical Note: This step requires patience and precision. Damaging circuit traces can permanently ruin the module.

Step 3: Adapter Connection

Proper adapter alignment is crucial:

Position the CAS3 adapter on the board

Align the bracket pins with the cleaned holes

Verify all pins make proper contact

Secure with plastic nuts

Double-check connections with extra lighting

Step 4: Reading Original Module Data

With the adapter securely connected:

Connect the Multi-Prog interface

Power on the device

Launch the Multi-Prog software

Select the correct processor type (OL15Y)

Use the “Pin Detect” function to verify connections

Read the EEPROM data

Read the Flash memory data

Save both files with clear identification (e.g., “OE adapter EEPROM”)

Important Note: If you see “CAFA CAFA” patterns in the data, you’ve selected the wrong processor type. The interface cannot decrypt the data properly with incorrect settings.

Step 5: Preparing the Donor Module

The donor module requires the same preparation:

Clean all contact points on the donor board

Verify processor type matches the original

Mount the adapter on the donor module

Test connections using the pin detect function

 

Step 6: Reading Donor Module Data

Before writing new data, read the donor’s existing information:

Read EEPROM data and save it

Read Flash data and save it

This provides a backup and confirms the module is readable

Step 7: Writing the Cloned Data

Now transfer the original data to the donor:

Switch to EEPROM mode

Open the original EEPROM file

Write the data to the donor module (erasing first)

Switch to Flash mode

Open the original Flash file

Write the data to the donor module

The process verifies the written information automatically. Success is indicated by a verification complete message.

Step 8: Post-Cloning Testing

After successful cloning:

Disconnect the programmer

Remove the adapter board

Place the cloned module on the test bench

Connect power supply

Test ignition cycling

Use diagnostic tools to verify functionality

The cloned module should now:

Switch ignition on and off reliably

Show the original VIN number

Clear all fault codes

Maintain stable terminal voltages

Function identically to the original

 

Important Considerations
Donor Module Quality

When purchasing donor modules, be aware that they may have similar issues to your original. A damaged donor might work temporarily before failing again. Always test thoroughly before relying on a cloned module.

Professional Tips

Organization: Mark modules clearly to prevent writing data to the wrong unit

Cleanliness: Proper cleaning of contact points is essential for successful reading/writing

Patience: Rushing the process leads to errors and potential damage

Verification: Always verify connections before attempting to read or write

Backup: Save all original data files before making any changes

 

Diagnostic Tools

While ISTA (BMW’s factory diagnostic software) can be used, bench tools like the Xhorse Multi-Prog are far more practical for this type of work, offering direct module access without the complexity of emulating a complete vehicle system.

 

Conclusion

BMW CAS3+ cloning is a delicate but straightforward process when proper tools and techniques are used. The key to success lies in careful preparation, precise connections, and methodical execution. While the process appears complex, following these steps systematically will allow you to successfully clone CAS modules and resolve BMW access system failures.

The ability to clone these modules professionally is invaluable for automotive technicians and enthusiasts dealing with BMW immobilizer issues. With the right approach, you can restore functionality to faulty CAS systems without expensive dealer interventions.

Remember: Always prioritize careful handling of circuit boards, verify your connections, and maintain organized files throughout the process. The investment in proper equipment and attention to detail will pay off in successful, reliable repairs.