6n2 polo engine start blocked by immobilizer

[rbrstr]

Hi,
Is anyone familiar with this fault? its causing the engine to cut out occasionally sometimes over bumps sometimes around corners. it makes 3 beeps when it cuts outs and can always be restarted, but its getting progressively more and more common now, doing it several times in a 30 min journey these last few day
the fault from my vcds lite reads "engine start blocked by immobilizer p1570"

[937carrera]

I'm not familiar with that particular fault, but it sounds like it's a poor connection (break in a wire somewhere ?) that makes / breaks when you go over a bump. Make sure the ECU / immobilisor / instrument connections are in good condition.

[alexperkins]

Can be due a faulty immobiliser ring around the key barrel or a faulty key transponder

[rbrstr]

still not making any progress with this despite checking all the connections and wiring as much as is possible. i have revisited the immo ring after Alex's advice and it quite wobbly but ive no idea if thats normal or not?
if i source a new immo ring and key chip second hand would i also need the immobiliser box and ecu also?
thank guys

[alexperkins]

Wobbly is normal

You'll need the ring and the immobox and ecu that all match

[rbrstr]

Many thanks for the replies its much appreciated, do i need to replace the speedo/rev counter binnacle also? someone has suggested i do? just wanted to check before i buy

[alexperkins]

I don't believe so. That was brought in on later models

[rbrstr]

I don't believe so. That was brought in on later models

ok thanks chap much appreciated

[rbrstr]

ok, so anyone know what is the difference between the AUA and AHW engines when they are both 1.4 16v? ive located a full ecu kit but its from the AHW but my sons is the AUA according to the boot sticker..

[rbrstr]

Okay so we have replaced the immobiliser and the immobiliser ring and ECU and the key chip but the problem still remains the same.does anyone have any ideas on other areas we can check? We have already checked all of the wiring loom and can find no problems

[alexperkins]

Are you still seeing an error in VCDS?

Can you communicate with the IMmobox ok with VCDS?

[rbrstr]

RESOLVED!
decided to service the car today and have another stab at fixing the issue after changing the oil,plugs and filters etc
While we were running on tickover to warm up the oil for draining, we could clearly hear something sparking periodically down the back of the engine. An investigation with a torch revealed that the main alternator to battery cable coming of the back off the alternator, which fits around the sump in a plastic clip on rail had become detached and had dropped onto the top of the drivers side driveshaft. the driveshaft had slowly worn into the cable shorting the car out over bumps and some sharp bends. cable was repaired and re-routed and the problem is now sorted

[937carrera]

Many thanks for posting a solution, it's always good to hear how things got fixed