I changed the ignition key transponder to fix the car not starting after driving for a few mins. The car ran perfectly for the last two weeks.

This morning, it refused to start altogether. It won't even turn. I never had a problem with the car not starting. The battery is in very good shape.

I'm getting transmission fault, fail safe mode, and incorrect part fitted.

I threw away the old part so I'm not sure if the new part of the problem.

The car is a 2001 XK8 with only 74k miles.

Thank you all

 

QUOTE: 'I changed the ignition key transponder to fix the car not starting after driving for a few mins.' END QUOTE.

I have a few questions for clarification, what led you to suspect the Ignition Key Transponder? By 'Ignition Key Transponder', are you referring to the tiny cylindrical module implanted into the key itself, or to the ring around the Ignition Cylinder that reads the key's implant? Did you perform the battery 'Hard-Reset' procedure after replacing the part? Some components can be disconnected and reconnected without having any adverse affect on the vehicles systems, other component replacements require a 'Hard-Reset' to allow the vehicle to properly calibrate to, and accept the new component. Does the car stop running while driving it, or after driving a few blocks/miles and park it, then when you return it will not start?

QUOTE: 'The car ran perfectly for the last two weeks. This morning, it refused to start altogether. It won't even turn. I never had a problem with the car not starting.' END QUOTE.

This is where things can get a bit complicated. Has the weather changed favoring warmer temperatures in the past two weeks including when the repair was made to the car, and it has been functioning normally? The morning the car would not start, had the temperature reverted back to a colder temperature the prior evening and that morning? This could be coincidence that the replacement of the Ignition Key Transponder fixed the vehicle, and the actual cause of the change to the car was the ambient temperature increasing this time of year, and thermal expansion that is related to the warmer weather. It could be a loose ground strap, or cable to the starter, I had the exact same undefinable problem on a Toyota I owned, and with the charging system on my Mercedes. The Toyota would just stop running while I was driving down the highway, and would not start for random periods of time depending on the outside air temperature, until it cooled enough to make proper contact. The Mercedes alternator cable was loose and would constantly drain the battery as I drove it, when it was warmer outside it made better contact and would drain the battery, but would take days longer; a couple of lock washers and a wrench fixed both problems permanently.

QUOTE: 'The battery is in very good shape.' END QUOTE.

Unless you have had the battery load tested, they do it free at Autozone, etc., you cannot be sure that there is not a problem with the battery, it's cables, or crimp connections at the clamps, terminal corrosion, loose connections and corrosion at the high voltage fuse block, and corrosion to the interior of all the aforementioned cables, starter cable included. These are all high suspect areas and generate the most common problems, error codes, and erratic behavior. The battery can be capable of starting the car and still be the problem.

 

Thank you 03 XKR for the comprehensive reply.

The reason I initially changed the exciter ring was to fix a problem with the car not re-starting every once in a while after driving for 10-15 mins and stopping for a few mins.

I only unplugged the negative battery cable for a couple of mins and reconnected it. The weather has been getting warmer since the repair.

I just read about the right hard reset procedure, I'll try it.

Thanks again
Jay

 

Thank you 03 XKR, I did a hard reset and it solve the problem.

I've been doing it wrong all along.

Thanks again

 

You are welcome, I am glad I could help. I hope this ends your starting issues altogether. I encountered a 'parasitic' drain on my car, capable of draining the battery in ~18 hours, that ended up being the Ignition Cylinder's 'Door or Flap', that was designed to close over the keyhole once the key is withdrawn, and enable the car to 'go to sleep'. It was gunked up with crap and needed to be cleaned with electronics cleaner and the 'door/flap' lubricated with an evaporate resistant penetrating oil.

 

Yes I just seen this thread and found out I had same issue (little door on key cylinder was staying open)I had just added a second battery and it would drain them both from 100% to 0% in just under two days and was causing window memory issues and keeping dash lights on and rolling quarter window down when I put key in ignition along with multiple codes scared the cap out of me

 

The 'good and the bad' unfortunately. When errant warning messages abound, and the windows forget their travel limit, it is a dead giveaway that there is a low battery issue. However finding the 'Parasitic Drain' causing the issue is not always an easy task as it can range from the interior of the battery cables being corroded or having a loose crimp at the cable end, to loose connections or corroded 'strap fuses' at the high voltage fuse block, or loose ground straps which have several locations throughout the vehicle; or in many cases, completely unrelated to the cables, and residing in the ignition cylinder.