My Octy wouldn't start this morning. When I turned the key nothing at all happened, no clicking noises, nothing. I jumped into my wifes car and took her to the station. When I got back I tried my car again and it started first time, as if nothing was wrong. All I can think is that the immobiliser must have stopped it starting.

Does anyone know if there are any common faults like this? Could it be something simple like the battery in the key being low?

nothing to do with the battery in the keyfob, that is purely to operate the remote locking - the key transponder is totally independent and unpowered.

If you have a real immobiliser issue, when you turn ignition on, the immo light will illuminate or flash on the dash - a car shape symbol with a key in it, orange colour.

The immobilizer wont stop the car starting, it starts then cuts out,

Sounds like a 109 main power relay to me.

When the 109 relay fails does it stop the engine trying to turn over? There wasn't any dash lights when I turned the key to try and start it..

My car wouldn't start again this morning. I took the key out of the ignition, pressed the lock and the unlock on the key, then tried again and it fired up first time. Does this still sound like a 109 relay issue? I might go to the Skoda dealership tomorrow and order new new one.

I think what ever is failing on my car has almost fully failed. Car wouldn't start in the petrol station earlier. When I tried the dash blanked, including the odometer. The car wouldn't respond to the buttons on the remote or the door lock button on the drivers door. It did come back to life a little opening and shutting the drivers door. This time the dash lights came on, but everything died when I turned the key to the next click to crank the engine. Eventually I disconnected and reconnected the battery and it started. Does this still sound like a 109 relay? I am waiting for the local Skoda dealer to call back with a price. Im worried it could it be a failing ECU?

Edited 10 November, 201015 yr by mrhclarke

The 109 relay provides power to the ECU, so if it fails there is no power to the ECU so nothing will happen when you try and start it.

From memory the relay is only about £15 from the dealer and takes 5 mins to change yourself.

I have managed to order one in for Friday. I am guessing it is a case of disconnecting the battery then swapping them over?

I don't think it's relay 109 in this case. You still get dash lights when relay 109 is faulty or not present.

First check the obvious

• Check the battery connectors are tight
  
• Check the fuses on top of the battery are OK/not loose
  
• Check for loose fuses in the fusebox at the end of the dashboard
  

My guess would be the ignition switch itself.

When it fails to start, turn the blower to full. With the key at the 'ignition on' position the blower should run but should go off in the 'start' position.

Edited 10 November, 201015 yr by rwbaldwin

But surely if it was the ignition switch the other electrics would still work? When the dash goes blank and it won't start even the remote lock and unlock stops working?

But surely if it was the ignition switch the other electrics would still work? When the dash goes blank and it won't start even the remote lock and unlock stops working?

You are correct. I missed the post about the central locking.

The central locking is unswitched so it must be one of following three things

• A bad connection between the battery and the relay panel - passes through one of the fuses on top of the battery
  
• The ground strap between the battery and chassis is loose
  
• The battery is intermittantly faulty
  

Edited 10 November, 201015 yr by rwbaldwin

My relay should be here for Friday, so I might as well fit it even if it doesn't fix it. I will check all fuses and the earth on the battery tonight too. Hopefully it isn't going to cost too much to fix, money is very tight at the moment...

You are correct. I missed the post about the central locking.

The central locking is unswitched so it must be one of following three things

• A bad connection between the battery and the relay panel - passes through one of the fuses on top of the battery
  
• The ground strap between the battery and chassis is loose
  
• The battery is intermittantly faulty
  

You're a genius! I took your advice and when I got home I decided to check the things you said. First I checked the negative to the battery when was tight. I then checked the positive and it basically fell off! Obviously when I changed the battery a month or so ago I had forgotten to tighten the positive connection. I reseated the positive and tightened it right up. Problem fixed! Starts perfectly... I guess the gap because it was loose was too big the the large power draw when trying to start the car. Thanks so much for your wise advice! I thought I had the same problem the Back To The Future Delorean had when it kept losing all power! I knew it couldn't be the flux capacitor though...