Keyless entry and start not working

Soldato
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Dude, try changing the battery. Honestly.

The Stop/Start on my Jaguar XE and XF both stopped working due to a dash camera. The car is smart enough to know the battery is a dud (or in my case being drawn on beyond the specification it left the factory with) and disable things that are additional draws such as emitting RF to find a key and to minimise load such as stop/start.

I wouldn't say Hyundai's are particularly known for it but I imagine they are as sensitive as other marques.
I’ve tested the battery with a multimeter, it’s between 12.3-12.5 when off and the car is locked. When I started the car the multimeter didn’t go below 10v which from Googling suggests it’s ok? It’s by know means a quality battery but it’s not failed me (so far) but I’ll keep a close eye on it. A new battery is £200 odd which I’d rather avoid for now.

The only other course of action would be the previous owner in his infinite wisdom (I mean seriously, the front page of motors has a chap who had his car nicked through keyless) removed the fuse for the sensor to disable the system totally. Smart.

I’ve tested the fuses, they’re all fine and in the right place. My other car is keyless and they’re kept in a faraday bag. I know it’s a ‘luxury’ feature but it bothers me that it doesn’t work, and it’s kept me occupied during lockdown. I quite enjoy tinkering.
 
Soldato
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I’ve tested the battery with a multimeter, it’s between 12.3-12.5 when off and the car is locked. When I started the car the multimeter didn’t go below 10v which from Googling suggests it’s ok? It’s by know means a quality battery but it’s not failed me (so far) but I’ll keep a close eye on it. A new battery is £200 odd which I’d rather avoid for now.



I’ve tested the fuses, they’re all fine and in the right place. My other car is keyless and they’re kept in a faraday bag. I know it’s a ‘luxury’ feature but it bothers me that it doesn’t work, and it’s kept me occupied during lockdown. I quite enjoy tinkering.
These are CANBUS cars that are much more sensitive than those that came before. Can you find a pal who has a battery to try out? If I wasn't worried about the consequence of taking my E43 battery out you could try that :p
 
Soldato
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Update: I can confirm it was in fact the SMK that was faulty! Once I removed my original smart key module it was fairly simple:
  • Load up diagnostic software (GDS)
  • Neutralise donor SMK by entering the donor car's PIN code. Luckily the eBay seller provided the VIN of the donor and I was able to calculate the PIN using a online calculator
  • Re-learn my the module and my keys using my car's PIN code, calculated online again.
Total repair bill was £141:
  • £82 for diagnostic software & VCI
  • £35 for donor smart key module
  • £24 for access to calculator for security pins
The hardest part was removing the old SMK as it's very awkwardly placed above the passenger footwell below the A-Pillar.

Pretty chuffed I managed to do it myself and took the gamble :cool:
 
Last edited:
Soldato
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21 Jan 2010
Posts
21,946
I'd probably try getting the supplying dealer to pay for the costs given they failed to diagnose and fix.
They already made him whole.

Update: I can confirm it was in fact the SMK that was faulty! Once I had removed my original smart key module out it was fairly simple:
  • Load up diagnostic software (GDS)
  • Neutralise donor SMK by entering the donor car's PIN code. Luckily the eBay seller provided the VIN of the donor and I was able to calculate the PIN using a online calculator
  • Re-learn my the module and my keys using my car's PIN code, calculated online again.
Total repair bill was £141:
  • £82 for diagnostic software & VCI
  • £35 for donor smart key module
  • £24 for access to calculator for security pins
The hardest part was removing the old SMK as it's very awkwardly placed above the passenger footwell below the A-Pillar.

Pretty chuffed I managed to do it myself and took the gamble :cool:
Good job. Well done. I'd still change the battery, though :p:eek:
 
Soldato
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They already made him whole.


Good job. Well done. I'd still change the battery, though :p:eek:

They've made me whole :eek::D? I don't want to count my chickens, but as I've managed to fix the keyless functionality for relatively little cost I'm tempted to replace the battery too. I can't explain why the original module failed. If the previous owner is to be believed it was working after he had the battery replaced in June last year before I purchased it in July. Coincidence that the module appears to have failed shortly after battery replacement?

I'd probably try getting the supplying dealer to pay for the costs given they failed to diagnose and fix.

The dealership I bought the vehicle from (a small private dealership) did provide financial compensation for the broken feature which was more than than my repair costs! I've sent a email to my local Hyundai garage who performed the diagnostics on it back in August to let them know their diagnostics were wrong and it was the SMK. I've not specifically requested a refund of the diagnostic cost (£79) but I did want them to know that their diagnostics were incorrect. I'll update the thread if they bother to get back to me.
 
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Soldato
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South of the Watford Gap!
Makes you wonder why the dealer diagnostics didn't find the fault, most likely because the person doing the diagnotics either didn't know how to use the software or didn't apply logic or both.

I'd be demanding the money back for the diagnostics as clearly failed to do what you paid them for.
 
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