Hi! I know this issue had been reported here many times before, but I have not found any "walk through" repair yet..  It is my wife who uses the car, and she have said that the car didn't start maybe two times before. When I checked the car started normally, until one day where I get the Immobiliser active fault. I have two original keys, and I tried both, then changed the batteries in both. Both batteries were good. I have a simple diagnose tool, and it reports "01176 key". The error shows up again immediately after beeing reset. The only other thing I have tried so far is disconnecting the car battery over night. Not sure what would be the best way to proceed the trouble shooting?

 

Removed the top panel around the steering coloumn, and partly the lower panel. Removed three screws from the lower panel, but couldn`t get the panel completely off because of the lever for the wheel height adjustment. Can the plastic knob on the lever be removed? Anyway, with the panels loose, the imobiliser error was gone! Engine starts normally. Unfortunately two other errors appeared. The ESP light, and a wheel shaped symbol. Maybe because the wheel height adjustment was loose? Will try some more tomorrow. Wiggling the wiring didn`t change anything, and I can`t see any damage.

Took the car for a ride, and the two "new" errors dissapeared! Very convenient to have a car that repairs itself. Strange..

Automatic repair didn`t last 😞 The immobiliser problem seems to depend on the temperature. Now we have rather mild weater (above zero), and no error. The wife said tha car wouldn`t start one day when it was colder. 

The CR2032 battery in the key fob has absolutely nothing to do with the immobiliser, the key fob can be considered as three separate devices, metal key, radio wave remote control for the central locking/alarm (convenience) system and transponder chip for the immobiliser in the instruments. This is a radio frequency chip which is inductively powered by the reader coil around the ignition switch. When it does not start, does it turn over, fire and immediately cut?

Hi!

Yes, it turns over, and runs for maybe two seconds, and stop. 

That sounds like the immobiliser triggering but should give a dash warning plus leave a fault code in the engine and instruments. If the instruments report a key recognition error on both keys, the usual problem on the PQ35 platform (Golf 5, Octavia 1Z etc) is a faulty reader coil around the lock. In theory these cannot be replaced, you have to fit a new barrel with new key so the pain of matching the new chip or order a VIN matched barrel which takes weeks to arrive (in the UK anyway). However it is possible to carefully press off the coil from the barrel of a universal lock and press it onto the removed original but if you kill it that is UK £150 down the drain when a matched barrel is UK £90.

Edited 17 March, 20242 yr by Crasher

Yes, the immobiliser triggers, and give message "Immobiliser active" on the dash. Fault code 01176 is generated.

Maybe this is the correct replacement part? https://www.autodoc.co.no/reservedeler/oem/1k0905865a?search=OEN+1K0905865A

 

No, that is just the switch which goes wrong all the time, I did one on a mk2 TT last week, but will not trigger the immobiliser. I ****ing hate Autodoc 🤨

Hmm, is the immobiliser coil part of the main part in the attached picture?

Edited 17 March, 20242 yr by cyberkul

You can change the ignition starter switch on some. I did on mine and I think I had similar problems but along with other issues I’m not 100% sure. 
1K0905865 for mine. 
Here is a pic of the old one out and stripped down. 

Edited 13 April, 20242 yr by Morph

Hi!

According to @Crasher 3 posts further up, the ignition switch would not cause the immobiliser fault, thanks anyway 🙂  I tried to troubleshoot by cooling down the area around the key with cooling spray, but I could not provoke the error to return. I think I`ll remove the instrument panel, and cables, and inspect for damages.

The immobiliser reader coil is the ring around the top of the barrel at the opposite end to the switch. You can’t buy these on their own, they come with a new barrels and to keep your single key operation these are a VIN dependent special order Vehicle Intelligent Part and take about two weeks to come through. However, if you buy a barrel with new unmatched key off the shelf, it is possible to VERY carefully push the reader coil off the new barrel and fit it to the original barrel once you have removed the old one.

Thanks! Is the reader coil glued to the barrel? 

Hi, i have the same problem for few years now, but it happens only in winter, when it is cold an there is this 1 sunny day where it maybe condesess or idk what and it wont start. Car usually starts normaly in cold or hot weather. Could it be reader coil, and if it is do you think would it be safe to buy it from aliexpress where it is pretty cheap? And, if i replase coil would i need any coding? I just found this on AliExpress: 

RSD3,108.64 | 5K0953254A Anti-theft Coil One-button Start Induction Coil For VW MQB EVO Golf Passat Touran Skoda Yeti Octavia For Adui A3 Q2

https://a.aliexpress.com/_EH5AIDQ

Edited 10 January, 20251 yr by IgorKovacevic

On 10/01/2025 at 17:04, IgorKovacevic said:

Hi, i have the same problem for few years now, but it happens only in winter, when it is cold an there is this 1 sunny day where it maybe condesess or idk what and it wont start. Car usually starts normaly in cold or hot weather. Could it be reader coil, and if it is do you think would it be safe to buy it from aliexpress where it is pretty cheap? And, if i replase coil would i need any coding? I just found this on AliExpress: 

RSD3,108.64 | 5K0953254A Anti-theft Coil One-button Start Induction Coil For VW MQB EVO Golf Passat Touran Skoda Yeti Octavia For Adui A3 Q2

https://a.aliexpress.com/_EH5AIDQ

As I understand it, the coil is just picking up the signal, and would not require any coding. The transponder is in the key fob, and is matched to the car. One day I couldn't put the key in the lock.  I dismantled the lock and instrument cluster, I didn't find any obvious damage in the instrument cluster. I managed to repair the lock, and when I installed it again, the immobilizer fault reappeared. I noticed that the wire to the immobilizer coil was ver tight. I pushed the steering wheel a bit forward, and the error disappeared when turning off and the on the ignition. Has not had any error since. I suspect the wiring.

The error came back🙁 It was not very cold, and it didn't help to move the steering wheel, to maybe move the cable to the the transponder coil a bit. The error was gone a litte later when my wife needed the car. She went shopping, and when trying to start the car she git the error again. She tried again after about 30 minutes, and the error was gone😳 So no I really has no clue what the problem is. Is the immobilizer matching with the key in the instrument cluster? Is it possible to use a instrument cluster, barrel and key from a scrap yard? Is it possible in some way to get rid of the immobilizer system? 
 

Hmm.. reading again what @Crasher wrote, I now understand it as the reader coil maybe just powers the rfid chip in the key fob, and the signal from the chip is received somewhere else?