VVDI Key Tool Plus BMW CAS4+ No Smart Function Solution

The car is a 2012 BMW 535i, F10 chassis, N55 engine, with a CAS4+ system. It arrives with a deceptively simple complaint: the key’s proximity function doesn’t work. Pressing the brake and the start button does nothing. To switch on the ignition, the key must be held against the induction coil. The customer bought the car this way, and a locksmith has already made a second key—which has the same problem. The remote buttons don’t work, and proximity doesn’t work.

Step 1: Test the Existing Keys

The first task is to determine the frequency of both keys—the original and the locksmith-made key.

Original key. On the Key Tool Plus, no frequency is detected at first. We note that CAS4 keys sometimes give up their frequency immediately when scanned, and tries holding the key to the coil.
The transponder reads as ID49—correct—but no frequency information comes through. Switching to KD Max to read frequency without pressing buttons: 315 MHz, which the technician expected for the vehicle.

Locksmith key. The second key’s transponder ends in 8124, and its frequency reads 433 MHz (later referred to as 464 in the discussion of the fob signal). That is the wrong frequency for this car.

A battery check follows. The original key’s fob has a battery and is sending a signal; the locksmith key’s fob has no battery and sends nothing. Swapping the battery into the locksmith key gets it transmitting at 464 MHz—but the vehicle still doesn’t respond. The technician’s working assumption at this point: either a coding problem, or the key needs to be programmed on the bench.

Step 2: Confirm the Vehicle’s Frequency

Using the Xhorse VVDI Key Tool Plus‘s “Fix remote/smart function” for the CAS4+, the technician pulls a critical piece of information: the vehicle frequency is 315 MHz. That confirms the original key had the right frequency, and the locksmith’s added key has the wrong one.

The tool also maps key positions: the locksmith key (3C928124, 464/433 MHz) sits at position three, while the original 315 MHz key sits at position six.

Step 3: Program a Correct Key

Select “Read ISN from working key”.  With the ISN retrievable from a working key (avoiding the need to go under the intake to the DME), the technician proceeds to prepare a dealer key.

Steps, as performed:

Go to “Fix remote/smart function”.

Select correct remote frequency.

Fix remote successfully.

Generate Autel BMW ikey.

In VVDI Key Tool Plus CAS4 menu, select Prepare dealer key with ignition switch.

Choose an empty key position (position 8, deliberately far from the others).

Confirm an original car key is available (yes) — used to retrieve the ISN.

Place original key into induction coil.

CAS4 auto-detect: select the encrypted version, as this is an encrypted CAS4+.

CAS auto-detect CAS type: choose option one, using the working key at the ignition coil to pull the ISN (rather than typing it manually).

Place the working key at the ignition switch; the tool reads the ISN.

Place the new key (the Autel Universal with the correct 315 MHz frequency and correct FCC ID) and complete learning.

Learning reports successful. The moment of truth: the remote responds—but with a noticeable lag, and it takes several presses. Proximity is detected, but only intermittently. The technician restores the previously backed-up coding (a step described as essential on a BMW), but the behavior doesn’t fully resolve. The remote works but doesn’t respond automatically; it takes multiple presses.

Step 4: Chase the Simple Stuff

Rather than assuming corrupted data or a deeper CAS fault, the technician turns to the basics—specifically, key fob battery voltage. The thresholds cited:

3.3 V — maximum charge, a great frequency

3.2 V — good

3.1 V — get ready to replace

3.0 V — intermittent problems

The original key fob, which had been in stock for some time, measures 2.9 V. The new battery measures 3.3 V. With the fresh battery installed, the remote locks and unlocks on the first press, every time. The start function works every time, including with the key placed elsewhere in the vehicle (back seat), confirming the interior antennas are detecting it. A brief “remote control not detected” message appears once even with the new battery, but the overall behavior is consistent and the technician considers it fixed.

The Verdict: Three Keys, Three Different Problems

The final summary is precise:

• Original key: right frequency (315 MHz), wrong FCC ID.
• Locksmith key: wrong frequency (464 MHz) and wrong FCC ID.
• Newly programmed key: right frequency and right FCC ID, but working intermittently due to a low battery (2.9 V).

The technician explicitly notes the temptation to conclude that someone read data and corrupted it—and the decision to check the simple explanation first. The key was programmed via OBD on the CAS4+ (encrypted, 5M/48H) using the Key Tool Plus. The case closes with the vehicle starting every time and the remote responding on the first press.

Takeaways

• Confirm the vehicle’s frequency before blaming the key. The CAS4+ reports 315 MHz; a 464 MHz fob will never work regardless of programming.
• Frequency is not enough—FCC ID matters. Two fobs can look identical and be for the same CAS4 family but carry the wrong FCC ID for the vehicle.
• A key that transmits is not necessarily a key with a good battery. Voltage thresholds (3.3/3.2/3.1/3.0 V) predict intermittent behavior directly.
• Back up coding before programming on a BMW, and restore it if behavior is abnormal.
• Check the simple things before chasing corrupted data. In this case, the “intermittent proximity” was a battery, not a corrupted CAS.

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VAG MQB49 5C Xhorse XSMQB Key Weak Signal Solution

Share the solution regarding the customer’s XHORSE XSMQB smart key weak signal issue.

“Read original MQB49 5C key data ok, but sometimes it doesn’t learn Xhorse XSMQB smart key. Xhorse has a wea signal and since it is keyless you need to disassemble the steering column and pop the Start/Stop button out. Then hold it close to the antenna and make sure the steering wheel is straight. Also use a Faraday Bag and if it still does not work, remove the battery when learning.

Faraday Bag is a small bag which has internal some layer as protected sheet so when you put KeylessGo key inside it will not allow data to come out from bag and you can not start the car. As soon as the key outside from that bag is, you can start the car.

While programming try to keep one key outside so no need to buy the bag

My last skoda even had problem learning back the original key and the remote wouldn work i programmed it like 30 times new until both Xhorse and the original Key worked properly.”

Read Skoda Scala 2023 MQB49 5C key with Xhorse

Problem:

Tried to read 5C key on a Skoda Scala from 2023.

But in Xhorse VVDI Key Tool Plus and Multiprog not the right PCB schematic.

Does anyone know the right connection diagramm ?

Here is the clue.

Pinout is attached.

Or use 5C solder free adapter without soldering.

XSMQB1EN works make sure you generate the right one.
Generate it under VW and all Remotes.

Xhorse Key Tool MIDI Program 2020 Ford Fiesta Smart Key

Adding a spare smart key to a 2020 Ford Fiesta is a straightforward process when using Xhorse VVDI Key Tool MIDI/Key Tool Plus. In this guide, we walk through the steps to add a new key to a Ford Fiesta after confirming that the original key was no longer working.

Step-by-Step Procedure
1. Select the Correct Vehicle Profile

Turn on the ignition and navigate to IMMO Programming- Ford- European- Fiesta- KeylessGo- 2018 onwards.

2. Prepare the Vehicle

The device will prompt you to open and close the driver’s door once, then turn the ignition off. Follow these instructions precisely:

Open the driver’s door and close it.

Switch off the ignition.

Press “OK” on the device to confirm.

3. Back Up the D-Flash

Before adding a key, the system requires you to back up the D-Flash. This step is critical for safeguarding the vehicle’s existing data.

4. Read the Current Number of Keys

The device will read how many keys are currently programmed to the vehicle. In this case, there were two keys already registered.

5. Add the New Key

Select the “Add Key” function. The system will remind you again to back up the D-Flash, which has already been done.

Important: Throughout the entire process, the ignition must remain off. All operations are performed with the ignition switched off.

6. Place the New Key in the Sensing Area

Locate the key sensing area inside the vehicle. In the Ford Fiesta, this area is marked with a key symbol. The presenter had already tested this area by removing the battery from a key, placing it in the sensing spot, and successfully starting the vehicle—confirming the sensing area works even without a key battery.

Place the new smart key in the sensing area and press “OK” on the device.

7. Confirm the Key Count

The device should now display that the current number of keys is three (the original two plus the newly added one). Confirm this is correct.

Testing the New Key

Once programming is complete, test the new key:

Use the new key to start the vehicle.

Then test the original key to ensure it still works.

Both keys functioned correctly after the procedure.

Key Takeaways

• Ignition must be off during the entire key programming process.
• Always back up the D-Flash before adding a key.
• The key sensing area in a 2020 Ford Fiesta is marked with a key symbol and works even if the key battery is removed.
• After programming, verify that both the new and original keys start the vehicle.

This method applies specifically to the 2020 Ford Fiesta using a compatible key programming tool. Always ensure your equipment and software are up to date for the best results.

Xhorse Multi Prog Clone Audi A6 C5 Cluster via BDM

Xhorse Multi Prog programmer new user review:

Audi A6 C5 cluster swap: cloned via BDM
On this cluster the immobilizer is built in, so the original EEPROM has to move with the car.
Motorola MC68HC912DG128A, read and written over BDM through 4 test points on the board: VCC, GND, BKGD, RESET.

There are already new replacement panels manufactured in 2008-2009, which have a regular backdoor button closed in the software. Only BDM will save them.