Mk2 25/45/ZR/ZS/TF BCU/SCU Relay Repair Kit - Pektron

If your Mk2 (04 onwards) Rover 25 / 45 or MG ZR / ZS / TF is suffering with the failure of the following, you probably have a failed BCU/SCU relay:

  • Front or rear foglights not working, or stuck on
  • Horn not working, or stuck on
  • Front or rear windscreen washer jets not working, or stuck on
  • Driver's side electric window not working correctly
  • Intermittent windscreen wiper not working correctly
  • Superlocking (deadlock) malfunctions
  • Central locking either not unlocking or locking (or both)

Removing the BCU unit isn't too difficult, but does require some dis-assembly. There are various guides on the Internet to help with this, but a quick summary is shown here:

  • 25/ZR - Remove the glovebox, and also remove the evaporator housing you'll see behind the glovebox. The BCU is located behind this. 
  • 45/ZS - Remove the centre console, and also remove the heater controls. You'll see the BCU behind these. 
  • TF - Remove one centre console side panel (passenger or driver's side) and you'll see the BCU - remove the screw holding the bracket in place, and slide the BCU out. 

Soldering new relays into place isn't too difficult, a small standard iron and a decent de-soldering braid will do the job. 

We'd recommend changing all of the relays if you can - as the problem has been identified in the past as a corrosion issue, it's likely the other relays in your BCU are affected to a degree.