Hitch retrofit

[jos]

I can‘t help with that you need someone experienced, did you read all in the chatgpt link?
I am not sure if you can mix Towbar and Module from different vehicles, possibly this needs to match or you need tricks, which may override safety. Do not give a shit on safety!

Post pictures of the sticker from the components!

Who ever may can help needs to know what you got.

KI asks me:

One quick question that could narrow it down a lot:

• What are the part numbers of your:
  
  • TRW module
    
  • towbar mechanism
    

Also, if possible:

• How many pins are in the connector on the towbar motor unit (usually 4 or 6)?
  

If we assume that the retractable towbar mechanism comes from a Volvo XC60, but it was installed in a Volvo XC40, the issue you are seeing is quite plausible.
The fault code
B14FB01 – Retractable Towbar Safety Switch – General electrical failure
usually means the TRM (Towbar/Trailer Module) is not receiving a valid signal from the safety/lock switch inside the towbar mechanism.
Your symptoms match this perfectly:

• The towbar deploys and retracts correctly using the switch
  
• But while driving, the car shows “towbar unlocked”
  
• The message disappears when the vehicle stops
  
• It happens regardless of whether the towbar is deployed or retracted
  

This usually means the lock confirmation signal is missing or incorrect.

---

Correct Towbar Module (TRM)
For SPA-platform Volvos like the Volvo XC40 (2018–) and Volvo XC60 (2018–), the retractable towbar is controlled by the TRM (Towbar Module).
Common Volvo part numbers include:

• 31454603
  
• 31346521
  
• 32369968
  
• 32386674
  
• 32414268
  

These modules are used across several SPA cars, including:

• Volvo XC40
  
• Volvo XC60
  
• Volvo XC90
  
• Volvo S60 / V60 / V90
  

So in many cases, an XC60 module can technically work in an XC40, as long as the hardware generation and wiring match.

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4-pin or 6-pin connection?
The OEM retractable Volvo towbar mechanism normally uses a 6-pin connector between the towbar mechanism and the TRM.
Typical signals in that connector include:

• Motor power (+ / −)
  
• Position sensor
  
• Safety/lock switch (locked/unlocked confirmation)
  

Because of these signals, the retractable system is normally 6-pin, not 4-pin.
A 4-pin connection is more typical for:

• simpler aftermarket systems
  
• or non-retractable towbars.
  

---

Most likely causes in your case
If the towbar is from an XC60, one of these is likely happening:

1. Different safety switch design in the XC60 towbar mechanism
   
2. Different pinout between the XC40 wiring and the XC60 towbar
   
3. Missing or incorrect lock confirmation signal
   
4. Coding expects different hardware
   

The TRM therefore thinks the towbar is not locked, even though mechanically it is.

---

 What I would check:

1. The exact part number of the TRM module
   
2. The part number of the towbar mechanism
   
3. Whether the towbar connector is 6-pin
   
4. Pinout of the safety switch line
   

---

? If you can provide:

• the TRM part number
  
• the towbar part number
  

it should be possible to determine quite precisely:

• whether the towbar is from an XC40 or XC60
  
• and why the safety switch fault (B14FB01) appears.