Immobiliser mischief? - Page 2

alan lloyd · 13th February 2008, 13:52

I am having exacly the same problem, doen't start randomly. Today started fine, travelled 50 miles , restarted 3 times, travelled 50 miles, stopped for lunch, refused to start.
I shall be trying again after sending this.
Is it possible to disengage the immobiliser?

alan lloyd · 13th February 2008, 15:24

After a 2 hour wait the engine has started, any views

David3807 · 13th February 2008, 15:46

As mentioned before Cam Sensor most likely the culprit when there is a hot start problem.

Quick test if car doesnt start when hot take off the cam sensor, place in fridge for 10 mins, and refit. If the car then starts you need a new sensor.

Greeners · 13th February 2008, 18:54

How about the under bonnet diesel pump.........??? Mine did this the other day, gentle "adjustment " with a hammer and it's been fine (Touch Wood)

Departed · 13th February 2008, 19:40

Quote:

Originally Posted by alan lloyd

I am having exacly the same problem, doen't start randomly. Today started fine, travelled 50 miles , restarted 3 times, travelled 50 miles, stopped for lunch, refused to start.
I shall be trying again after sending this.
Is it possible to disengage the immobiliser?

No. It would be a bit pointless if you could overcome it without major trauma.

EamonnS · 19th May 2008, 16:03

My 75 Tourer has just started playing me up with the immobiliser. What triggers the transponder chip when it is in the ignition lock? Is this a passive transponder or does it rely on a battery in the key? Is there a way of completely bypassing the immobiliser? This is now happening with both of my keys. HELP!!!!!

Quote:

Originally Posted by lowedb

Immobilser and locking aren't actually linked (other than they both live inside the key head).

The alarm / locking transmits when you press they fob. The immobilser has a transponder chip which only transmits when it's in the ignition lock. The ECUs that receive the signals are different too.

So sorry, the theory doesn't stack up, and as pointed out an immo lockout also prevents cranking.

Simon · 19th May 2008, 17:15

In what way is your car playing up? A list of the symptoms will help diagnose the problem as it may not be immoboliser related - for example other electrical gremlins can produce strange results.

Departed · 19th May 2008, 18:57

Hi. The transponder doesn't rely on the battery. The coil around the ignition lock transmits a signal to the chip. The chip powers itself from this signal, and modulates the signal to talk to the immobiliser. The immobiliser also modulates the signal to talk to the chip. It's triggered as you turn the key from off, to accessory.

The battery is for the remote control: in the same box as the transponder, but not connected to it. The transponder has nothing to connect it to anything. You could take the battery out, and the transponder will still work. In fact early cars were meant to have one normal key an one key with only a transponder. Don't know whether this ever happened, but it would explain why so many early cars have only one key.

As I said earlier, the immobiliser would be a little pointless if it could be overcome without a good deal of effort: whoever wanted to steal your car would simply switch off the immobilser and drive your car away.

Kingfisher · 6th September 2008, 22:50

Like many of us I have suffered the frustration, although rarely, of the starting problem. Usually resolves itself after being left alone for periods of time but still left me baffled. Tonight it happened again. RAC man turned up and immediately stated that he had dealt with this problem before. Popped the bonnet and tapped the top of the fuel pump. I turned the key and the old girl fired up immediately.
I have had my 75 since new (6 years) and 65,000 miles later I still believe it is one of the finest cars on the road. Hope this helps.

Simon · 6th September 2008, 22:55

to the Club Paul.

Thanks for the informative first post. As you have discovered - a sticky/failing underbonnet pump can cause starting issues. A quick tap unsticks it. Other fuel-related issues include the other fuel pump in-tank (where fitted) and the fuel filter which can come unscrewed (this is a simple fix with £2 spare part fitment to prevent repeat unscrewing).

Hope you enjoy your stay here - plenty to read up on and do if you haven't already seen.

13th February 2008, 13:52	#11
alan lloyd Newbie rover 75 touring cdi Join Date: Feb 2008 Location: Farnham Posts: 12 Thanks: 0 Thanked 0 Times in 0 Posts	immobiliser mischief I am having exacly the same problem, doen't start randomly. Today started fine, travelled 50 miles , restarted 3 times, travelled 50 miles, stopped for lunch, refused to start. I shall be trying again after sending this. Is it possible to disengage the immobiliser?

13th February 2008, 15:24	#12
alan lloyd Newbie rover 75 touring cdi Join Date: Feb 2008 Location: Farnham Posts: 12 Thanks: 0 Thanked 0 Times in 0 Posts	Immobiliser, non starting After a 2 hour wait the engine has started, any views

13th February 2008, 18:54	#14
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	How about the under bonnet diesel pump.........??? Mine did this the other day, gentle "adjustment " with a hammer and it's been fine (Touch Wood) __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

19th May 2008, 18:57	#18
Departed Retired -- Join Date: Jan 2007 Location: -- Posts: 3,785 Thanks: 0 Thanked 4 Times in 4 Posts	Hi. The transponder doesn't rely on the battery. The coil around the ignition lock transmits a signal to the chip. The chip powers itself from this signal, and modulates the signal to talk to the immobiliser. The immobiliser also modulates the signal to talk to the chip. It's triggered as you turn the key from off, to accessory. The battery is for the remote control: in the same box as the transponder, but not connected to it. The transponder has nothing to connect it to anything. You could take the battery out, and the transponder will still work. In fact early cars were meant to have one normal key an one key with only a transponder. Don't know whether this ever happened, but it would explain why so many early cars have only one key. As I said earlier, the immobiliser would be a little pointless if it could be overcome without a good deal of effort: whoever wanted to steal your car would simply switch off the immobilser and drive your car away. Last edited by Departed; 19th May 2008 at 19:00..

6th September 2008, 22:50	#19
Kingfisher Newbie rover 75 saloon Join Date: Sep 2008 Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	Diesel Intermittent Strating problems Like many of us I have suffered the frustration, although rarely, of the starting problem. Usually resolves itself after being left alone for periods of time but still left me baffled. Tonight it happened again. RAC man turned up and immediately stated that he had dealt with this problem before. Popped the bonnet and tapped the top of the fuel pump. I turned the key and the old girl fired up immediately. I have had my 75 since new (6 years) and 65,000 miles later I still believe it is one of the finest cars on the road. Hope this helps.

13th February 2008, 15:46	#13
David3807 Posted a thing or two 2002 R75 Conn SE 2.5l Auto Tourer, 2001 R75 Conn SE 2.5 Auto Saloon Join Date: Nov 2006 Location: Gravesend Posts: 1,897 Thanks: 0 Thanked 2 Times in 2 Posts	As mentioned before Cam Sensor most likely the culprit when there is a hot start problem. Quick test if car doesnt start when hot take off the cam sensor, place in fridge for 10 mins, and refit. If the car then starts you need a new sensor.

19th May 2008, 17:15	#17
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	In what way is your car playing up? A list of the symptoms will help diagnose the problem as it may not be immoboliser related - for example other electrical gremlins can produce strange results.

6th September 2008, 22:55	#20
Simon Banned - Join Date: Nov 2006 Location: - Posts: 10,318 Thanks: 0 Thanked 4 Times in 3 Posts	to the Club Paul. Thanks for the informative first post. As you have discovered - a sticky/failing underbonnet pump can cause starting issues. A quick tap unsticks it. Other fuel-related issues include the other fuel pump in-tank (where fitted) and the fuel filter which can come unscrewed (this is a simple fix with £2 spare part fitment to prevent repeat unscrewing). Hope you enjoy your stay here - plenty to read up on and do if you haven't already seen.