I posted in March about the check keyless entry error I was getting and then the car stopped recognising both keys.
I located the RFHM unit from the boot and could see a little corrosion on the connector and on the PCB itself.
I took the RFHM unit to a local auto electrician who said it was quite badly damaged, but he re-soldered some of the connectors and gave it back to me to try, with no warranty.
I put it back on the car and the keys were recognised again and I could use them, but was still getting the check keyless entry error.
I could see from looking at the RFHM installation that it could allow water to follow down wires into it. I re-routed the wire into it a little so it created a loop back up into the RFHM, so water in theory couldn't track back up into it.
So, I'm still getting the check keyless entry error, but the keys are still recognised and work, so I haven't bothered getting it resolved any further. I guess I'm nervous or paying £800 getting a new module just for it to get water damaged again.
You need to tend to the actual cable end connectors as well. Cleaning the circuit board and circuit board connectors is OK but the cable end connectors will be corroded / tarnished a as well.
I thought in my post that I mentioned in detail how I cleaned and lubricated the circuit board connectors and the cable end connectors. Anyway here is the info again:
12/09/25 - Fault - "Check Keyless Entry System" error on dashboard.
0032,298
MaxiECU Had: B1035-01 : Button Pressed - General Electric Failure
MultiECUScan Had: B1035-01 : External handle input for Passive Entry - General Electrical Failure
Fiat 500X eLearn diagnostics has: Button Pressed - General Electrical Failure B1035-01
o Stripped down boot rear end cover and LHS boot trip and carpet wall
o Notice water on the module case
o Removed RFHM complete with carrier frame
o Removed connectors - slide grey tab backwards and depress latch head/button
o Removed module from frame, opened module case and removed circuit board
o Smaller LHS connector has mild corrosion on lower end pins
o Larger RHS connector looks dry and clean
o Used alcohol and small wire brush to clean pins
o Repeated with switch cleaner and lubricator
o Gently scrapped all pin side with small file
o Re-lubricated with switch cleaner and lubricator
o For both connectors applied alcohol and blew through with compressed air
o For both connectors applied switch cleaner and lubricator
o For both connectors inserted/removed flat electrical matching connector pin several times
o For both connectors applied switch cleaner and lubricator again
o For both connectors connected / removed from RHFM module
o Checked with MaxiECU that fault was fixed
o Replace RFRM *without* frame and rotated through 90 degrees using only lower mounting stud but
with neoprene pad tie wrapped to underside of the RFHM
o With the module in this position the larger connector and cable are facing down. The upper
connector cable has a nice cable drip loop
o Covered the whole assembly and cables with a thick polythene sheets. These slide up behind the
seat belt reel and goes over the module and wires down into the inner wing. The sheet are secured
using the un-used frame mounting studs.
o Test again
o Put all trim back