transponder chip

roy 1953 · 26th April 2021, 20:13

Hi all,
I have another problem or 2 I need help with, The other day, went to car, remote would not unlock car, got spare which unlocked car but would not start it, engine disabled message. opened up case and transponder chip is present.
I think it worked when I bought the car 2 years ago.
so now I have a key with the transponder chip from the first key and the circuit board from the second and all works ok, so the spare key has a faulty transponder chip and a faulty unlock switch.
Can the transponder chip lose sinc with the car?.
And, on a separate note can the radio lose contact with the steering wheel controls after a battery disconnection?. Because mine seems to have done so!.
Thanks
Roy

T-Cut · 27th April 2021, 09:27

Hello Roy, this post might help with your key issue: https://www.the75andztclub.co.uk/for...d.php?t=106447

TC

SD1too · 27th April 2021, 09:33

Hello Roy,

With the first key which would not unlock your car; could the battery need renewing?

Simon

roy 1953 · 27th April 2021, 14:52

Hi tc, yes, that appears to be the problem, but car battery is absolutely fine, is there another way the chip can get scrambled except for trying to start car with failing battery?. As I don't want it to happen to my other key.

roy 1953 · 27th April 2021, 14:57

Hi Simon, no, battery is ok, led on fob is lit with lock button but does not illuminate with unlock button, I suspect the switch on board might be u/s.
Roy

stevestrat · 27th April 2021, 15:09

You may be right about the unlock button. They can be replaced. Best to speak to one of the key guys on here.

The spare key, is it the genuine spare or a later replacement, if so where did it come from? Some key copies are "dodgy", coding a transponder without the proper equipment results in a "clone" with a limited life which will drop out of sync with the car's security system rather than a fully coded transponder.

roy 1953 · 27th April 2021, 15:30

Hi Steve, as far as I know it is a genuine key.
Roy

cb750chris · 28th April 2021, 12:28

Hi Roy,
Sent you a PM to see if I can help you.
Regards

Chris

26th April 2021, 20:13	#1
roy 1953 Regular poster rover 75 saloon Join Date: Mar 2019 Location: Kidwelly Posts: 59 Thanks: 4 Thanked 7 Times in 7 Posts	transponder chip Hi all, I have another problem or 2 I need help with, The other day, went to car, remote would not unlock car, got spare which unlocked car but would not start it, engine disabled message. opened up case and transponder chip is present. I think it worked when I bought the car 2 years ago. so now I have a key with the transponder chip from the first key and the circuit board from the second and all works ok, so the spare key has a faulty transponder chip and a faulty unlock switch. Can the transponder chip lose sinc with the car?. And, on a separate note can the radio lose contact with the steering wheel controls after a battery disconnection?. Because mine seems to have done so!. Thanks Roy

27th April 2021, 09:33	#3
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,367 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Roy, With the first key which would not unlock your car; could the battery need renewing? Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

27th April 2021, 15:09	#6
stevestrat This is my second home ZT260 #243 (resting) Join Date: May 2010 Location: Prestonpans Posts: 22,473 Thanks: 650 Thanked 4,624 Times in 3,358 Posts	You may be right about the unlock button. They can be replaced. Best to speak to one of the key guys on here. The spare key, is it the genuine spare or a later replacement, if so where did it come from? Some key copies are "dodgy", coding a transponder without the proper equipment results in a "clone" with a limited life which will drop out of sync with the car's security system rather than a fully coded transponder. __________________ Steve T4 Location Map

28th April 2021, 12:28	#8
cb750chris Trader Rover 75 Tourer Join Date: Apr 2011 Location: Portsmouth Posts: 849 Thanks: 201 Thanked 292 Times in 200 Posts	Hi Roy, Sent you a PM to see if I can help you. Regards Chris __________________ Now offering T4 services in the Fareham area Replacement keys programmed / supplied / cut Diesel 135 upgrade available IPK virginisation and T4 matching available Sorry, due to a big change in home circumstances, I am unable to do any large jobs at present, but can still offer evening time diagnostics.

27th April 2021, 09:27	#2
T-Cut This is my second home Rover75 and Mreg Corsa. Join Date: Nov 2006 Location: Sumweer onat mote o'dust (Sagin) Posts: 21,752 Thanks: 341 Thanked 3,660 Times in 2,924 Posts	Hello Roy, this post might help with your key issue: https://www.the75andztclub.co.uk/for...d.php?t=106447 TC

27th April 2021, 14:52	#4
roy 1953 Regular poster rover 75 saloon Join Date: Mar 2019 Location: Kidwelly Posts: 59 Thanks: 4 Thanked 7 Times in 7 Posts	Hi tc, yes, that appears to be the problem, but car battery is absolutely fine, is there another way the chip can get scrambled except for trying to start car with failing battery?. As I don't want it to happen to my other key.

27th April 2021, 14:57	#5
roy 1953 Regular poster rover 75 saloon Join Date: Mar 2019 Location: Kidwelly Posts: 59 Thanks: 4 Thanked 7 Times in 7 Posts	Hi Simon, no, battery is ok, led on fob is lit with lock button but does not illuminate with unlock button, I suspect the switch on board might be u/s. Roy

27th April 2021, 15:30	#7
roy 1953 Regular poster rover 75 saloon Join Date: Mar 2019 Location: Kidwelly Posts: 59 Thanks: 4 Thanked 7 Times in 7 Posts	Hi Steve, as far as I know it is a genuine key. Roy