Technical Remote Key Fob Not Locking, Intermittently

[AMMJ]

Hi, I just I wondered if anyone had come across this particular problem on any recent Fiat or indeed even any car. My key fob, say about 50% of the time, refuses to lock the car. This behaviour just suddenly started about a couple of weeks ago.

Before you ask, I have now changed the battery in the remote twice, making no difference. The key fob will unlock the car without any problems 100% of the time but intermittently will not lock the car leaving me pressing the button over and over. Sometimes I give up & just use the drivers door lock switch or else sometimes it starts working again after the umpteenth go and works fine for that period, even a long distance away from the car. It seems totally random but more often than not it won't work when I leave the car and I can't figure out what changes when it suddenly starts working again. I am thinking some malfunction within the remote, dry joint? capacitor?, but the randomness throws me a bit. I wonder if the receiver in the car is just not recognising it somehow, a software thing... I think I'm going to have to bite the bullet and approach a dealership, as not even some kind of clue has surfaced, but I know a replacement remote can be up to £300, so you can understand my slight reluctance.... I can't even think of a way to test the remote (some manufacturers provide two)

The only other thing that has happened but I'm assuming is completely unrelated, is that the main car battery went kaput, (a long way from home...would no longer take any significant charge) last weekend, leaving me stranded. I made it home thanks to a boost start from Green Flag... (Driving batteryless threw up plenty of odd behaviours and fault messages on the meters!) ...and then I replaced the 12v battery (Eurocarparts Lion 027, very similar Ah and CCA as the original)... and all else seems well & normal again but this particular fault was there before and after with no change...

P S, when I took the original battery out to have a go at bench charging it for a short while, it occurred to me that with the doors now locked and the car not having any electrical power, DON'T SHUT THE BONNET! As how do you get into the car to open the bonnet again and refit the electrical power source... My neighbour reckons that if this happens there is a little manual trick switch lock somewhere on a normally hidden part of the door handle but I don't know....

 

[chris3234]

There's no hidden key lock on the car
There's a clearly visible None hidden one on the driver door handle however


As for the remote ID try dismantling it and cleaning the switch's with contact cleaner hopefully it's just a build up of crud on them stoping them working correctly

 

[RalphM]

Take it it's a separate button for lock, open the key and have a look
at the switch under the lock button there are 4 connections look for
any cracks across the joints,
The switches can fail and need replacing depends on how good your soldering is.

 

[AMMJ]

Thanks for replies. I'll have another look, carefully. I did preliminarily try taking it apart last week but after removing one small screw under the main cover, a rubberised portion that it seemed to hold in place refused to budge... A little worried about using excess force. I suppose nothing ventured....

Chris I didn't quite understand your second paragraph about the possibility of getting in to the car when locked with no electricity.

Never had a remote go bad on me before.

 

[chris3234]

Thanks for replies. I'll have another look, carefully. I did preliminarily try taking it apart last week but after removing one small screw under the main cover, a rubberised portion that it seemed to hold in place refused to budge... A little worried about using excess force. I suppose nothing ventured....

Chris I didn't quite understand your second paragraph about the possibility of getting in to the car when locked with no electricity.

Never had a remote go bad on me before.

There should be a lock barrel in the driver's door handle that's clearly visible and not under any sort of cover

Never seen one without

 

[AMMJ]

Chris, I just checked it with the battery disconnected....and you're absolutely right, it does unlock, so apologies for leading folks down the wrong road with that one! I must have been a bit panicky on the grim (dead car) night I took the battery out to try and charge it.

The remote, I did manage to separate the halves of shell but not completely, couldn't work out the metal key ring bit. However blew into the circuit board, put it back together...and it seems better, has worked 99% since but not quite 100...It's annoying - I could have improved it or...it's just about to quit again. I won't be sure for a day or two. I may however to get some WD40 specialist contact cleaner and repeat the process....Cheers for suggestion.

 

[AMMJ]

Update...I got some specialist contact cleaner into the opened shell case of the key fob but...made no difference whatsoever in reality. Still the same intermittent problem despite seeming promising after the treatment. I couldn't however be absolutely sure it was a fault with the key fob...until a YouTube video gave me an idea. Set my old kitchen TV to analogue and tuned it to 433.75 MHz, hit the remote button and hey presto the TV picks up the signal. When a period arose when it refused to lock the car, I tried the same TV test to reveal that it definitely is the remote key fob that is faulty. However it works mysteriously maybe 75 to 80% of time...so...I probably continue with it despite the occasional annoyance... for now.

 

[AMMJ]

£310 to obtain a new key fob including coding from Fiat..!

 

[penllyndyfi]

On my Tipo estate the drivers door does not lock either with key or remote but other 4 work fine. I cheked the fuses behind the glove box ( a difficult task) and was confused by a bank of 5w fuses( not 7.5s identified in User Manual). No fuses blown so investigated door lock. On removal (which was also difficult) I find that the plastic part of the lock assembly has cracked and maybe at least some part of the explanation for the locking failure. Unable to repair it with supaglue there must be a lot of stress on this part : there is a portecting bar fitted to reduce the lock body but its positioning isn't great. Have now ordered a replacement locking assembly from a scrappie ; the part is on back order at Fiat.
The level of parts availability is so so poor on Tipo.

 

[chris3234]

On my Tipo estate the drivers door does not lock either with key or remote but other 4 work fine. I cheked the fuses behind the glove box ( a difficult task) and was confused by a bank of 5w fuses( not 7.5s identified in User Manual). No fuses blown so investigated door lock. On removal (which was also difficult) I find that the plastic part of the lock assembly has cracked and maybe at least some part of the explanation for the locking failure. Unable to repair it with supaglue there must be a lot of stress on this part : there is a portecting bar fitted to reduce the lock body but its positioning isn't great. Have now ordered a replacement locking assembly from a scrappie ; the part is on back order at Fiat.
The level of parts availability is so so poor on Tipo.

Very true especially in the UK had to buy shocks from Germany a few month back as nobody sold them in the UK and Fiat said 6 weeks