75ZT Community

Hi there, bought a 2002 75 diesel. Had it one day and the key blade fell out somewhere?? Got someone to recut a key using the door lock. Turned the new key blank with the old fob and happy days it started and everything seemed ok. Then put all the fob internals into the new key and tried to start it about 10 times with no luck got ignition but wouldn't start. I then noticed I hadn't put the transponder chip in the new key. I never knew it was separate. I then added it to the new key and tried again. All the dash lights flickered on and off very rapidly without the car starting. I tried this again a few times and the same thing happened. I then removed the chip, put it in the original fob and used the blank again as I did at the start. Got dash lights everything is as normal and functioning but starter still not turning over. I tried all different ways to get this to work with no joy. Finally got the chip tested to see if it was ok and it is working fine. Can anyone HELP? Does the immobiliser need reset because I tried it without the transponder chip. MANY THANKS.

Most of our experts are at a meet in Cosford today, they should be back on early evening.
"Monk" is the key wizard if that is the problem, if not, there are others that can help.
With regard to flashing lights, if your battery is not producing enough power to start the car, dash and headlights will flick on and off 3 times. This is just a guess at a possible additional problem, I'm no expert.

If I'm honest it sounds like a battery problem. The transponder being missing shouldn't cause the dash lights to flicker, and as far as I know you don't reset the immobiliser. At least I didn't need to when I tried a key with the wrong chip in it to see what would happen. I just got a message on the dash something along the lines that the immobiliser was active.

Hi there, the dash lights only flickered when the transponder was put back into the key. Half an hour before this all was well with the old fob complete with transponder (no key blade) and the new key used in close proximity. Only when I switched the fob stuff over and forgot the transponder did it not turn the starter. Then when i put the transponder in as well all the dash flashed in and out like a bad connection. I then put everything back to when it was turning the car starter (original fob and new key) and put jump leads on from another car (Just in case as the battery seems fine) as well but it does everything it should except turn the starter over. It all started (maybe coincidental) when I put the fob internals into the new key(and forgot the transponder).

I believe if it is a transponder problem the engine immobilized notice comes up if you have the message centre option, it may be that if you don't have this then the lights do indeed flicker, (Duncan??) and the engine will not turn over.

I don't have the message centre option and the lights only flicked on and off a few times amongst all that i mentioned above now i am back to everything working but the starter not turning over. I'm stumped, got a mobile locksmith to check the transponder and he said it is working. I saw the readout on his machine. I will try a new battery tomorrow but the one that is in it is appearing to be strong. It's been parked 12 miles away for 6 days now, outside a friends right enough.

Dave, you may be right though I've not heard of this. Both my cars have hiline packs so I can't check. The workshop manual doesn't say anything other than the starter is disabled, and messages on the hiline. There isn't a separate lamp on the lo-line pack from what I can see.

EDIT: I've found another section that says there is NO visible or audible indication of the immobiliser system status unless you have a highline pack when you get the 'engine disabled' message. So that suggests the flashing of the instruments is some kind of fault. It could be an earthing problem as I reckon the Immobiliser shares an earth with the rest of the dash. Also, the immobiliser cannot cut power to the instruments or other systems. It can only prevent the starter motor from operating, and tell the engine ECU (Engine Control Unit) not to allow the engine to start.

It is also possible you have a faulty starter motor / solenoid, or possibly the relay in the immobiliser ECU. I have only come across the faulty relay once, the starter solenoid is much more common especially on diesels.

The electrics have never flashed like this again it only happened the once.

Hi Duncan. Wouldn't the solenoid click?

Hi Gary,

Having read through the whole thread again i would be inclined to think the immmobiliser is a red herring, i think it is just coincidence and the likely culprit will be the starter solenoid. Very common problem, repair kits are available on ebay for under £15. If the headlights flash when you turn the key then that is a sign of a flat battery. Other cause can be the light duty wire that goes to the solenoid, the connection may need a clean as sometimes happen.

Where are you based?

Hi there, I am in south west Scotland. I have an update. Put a new battery in as it was well down. Tried all again without any joy. Got someone out with an analyser (snap on) and it showed immobiliser faults he cleared them but it still was the same. Also he cannot get rid of the immobiliser fault reading it won't wipe? It's been suggested that the rolling numbers system and the transponder have got out of sync and it needs reset due to me repeatedly trying it initially without the transponder in the new key. .??

If the battery has gone flat and repeated attempts to start the car are made it can scramble the codes between the EWS (Engine immobiliser (EWS from the German, Elektronik WegfahrSicherung)) and Transponder. Although on the hi-line it would display the immobilisation error, and I believe there is an engine light with exclamation mark in it for the lo-line. Anyone confirm I can't remember?

What visual symptoms other than a non starting car are showing with a new battery? Are the lights still flickering?

The illuminated lightbulb was on that was the only thing that was illuminated on the dash. I put the new battery in and it was still on but has since went off. Now everything seems back to normal just not turning the car over but the diagnostic keeps coming up with immobiliser fault. So I guess it looks like a reset?? Oh I forgot no lights flickering that's never happened again. Do you know the procedure for a reset?

It does sound as if you have scrambled the transponder codes with a failing battery. It has happened on a few occasions.

You need to find someone who can code keys from the EWS. Local high street shops will be a no no, you will need an auto-locksmith. If you were closer I could do it for you. A member called Russ is closer but he is in Yorkshire so still quite far. I'm not sure if anyone on the boards is closer and can do the reset. A dealer won't be able to do it either unfortunately, they'll simply fob you off as needing a new key. Have a Google for local auto locksmiths and ask them if they can code a transponder from the Immobiliser in your Rover 75 as the current one is possibly corrupt. Have a look for any that won't charge unless they supply you with a working transponder as then if it isn't the transponder that's causing the mischief you may get off with paying less or even nothing.

Thank you very much. I will get an auto locksmith and see how I go. Hope that's a fix. Thanks to all for the helpl