Right another niggle has reared it's ugly head. This year so far I have replaced the camshaft sensor, MAF and hazard relay.

Early last week I started the car and it stopped immediately, restarted and it was fine. Checked codes and got the above mentioned one. A couple days later and it happened again so I changed keys as I had dropped mine prior to this happening and assumed possible damage to the transponder.

Today I got in the car and it took no less than 3 attempts to start the car, the dash light for the immobiliser was flashing away during each attempt.

Ross Tech wiki gives me this:

17978/P1570/005488 - Engine Start Blocked by Immobilizer

Possible Symptoms

• Engine starting but stalling immediately
  

Possible Causes

• Key(s) not matched
  
• Instrument Cluster not matched
  
• Engine Control Unit (ECU) not matched
  
• Engine Control Unit (ECU) Power Supply faulty
  

Possible Solutions

• Check for Fault Codes in Immobilizer itself (part of Instrument Cluster in many cars, but separate Immobilizer Control Module in some)
  
• Check Immobilizer Measuring Values (usually in Instrument Cluster OR Immobilizer Control Module)
  
• Match Key(s)/Instrument Cluster/Engine Control Unit (ECU)
  
• Check Engine Control Unit (ECU) Power Supply (Relay)
  

I'm assuming the ECU relay is the most likely. Memory is vague but is it the 109 or 409 relay? Any idea how much one would be roughly?

Ok I have done some checking and now know it's the 109 relay that I may want, don't know what was making me think 409 :confused:

I should have pointed out that the code has accompanied every failed start not just the first time.

I have done a cold reboot as suggested on Ross Tech's site and will see how it goes.

Here's hoping

Does anyone know the location of the 109 relay? Thought it was behind the dash under the steering wheel but it is not there :confused:

its in the engine bay mate at the back under the cover next to the passenger strut:thumbup:

I had a look there and there is 2 relays, 1 is labelled 100 the other is 428, which one of those is it Clive?.

Definitely do not have a 109 relay and the 409 is the fuel pump relay so it's not that one.

I had a look there and there is 2 relays, 1 is labelled 100 the other is 428, which one of those is it Clive?.

Definitely do not have a 109 relay and the 409 is the fuel pump relay so it's not that one.

OK done some digging and it seems the 100 relay is for secondary air pump and 428 is for the ECU.

sorry mate

havent got a clue in that case just looked at mine cant see a 109 relay:O

I think I may have been looking at the wrong thing. There is a loom from ignition switch to dash pod that can cause this fault. Will look into replacing that.

Anyone know any more on this loom or the part number, it would appear it's a weak link on octi's and fabia's and can get stretched when the steering wheel is extended.

I thought 109 was up under the steering column somewhere - in the middle of a row of three relays.