98 Audi A6 2.4 V6 non start 17978 code

[AutoRen]

Hi Guys I am new to this site found you after much searching on the web trying to get to the bottom of this fault.
I have read many similar post but have drawn a blank.

I have replaced the faulty ignition switch, and key fob batteries, have tried the key reprograming but all I managed to do was disable the central locking ???
I don't think this is the problem as the car came to me running with no fuse in central locking anyway.

First I have to turn on ignition a couple of times to get the immobilizer key symbol light to go out and stay out, the engine turns over but will not fire.

After scan I get

17978 engine start blocked by immobilizer P1570
static no indicator

also on 17

01176 Key
static signal too small.

I suspected the two wire loom from the key coil to the immobilizer as I have read this is a known issue on A8's and some TT's. But this fix is not applicable to this model.
Any help with this would be gratefully appreciated as this has been stuck outside the house for some weeks now !

[towcestervag]

yes it is!
remove the terminal from ignition barrel and tighten the connections

[AutoRen]

Thanks I will give it a go.

[AutoRen]

Ok I'm getting round to the idea that this is not an immobilizer fault after all,
forgive me if i'm wrong but surely the immob will allow the engine to start but then cut out shortly afterwards ???

I can crank the engine and it sounds like it is trying to fire, I can smell fuel so I know thats not the issue, I am now fairly sure this is either a crank position or cam position sensor fault, I know they have their respective fault codes neither of which are registering I have had this happen on a merc.

To save me a lot of time can someone tell me where the CPS is located on the V6 ? I have spotted the cam sensor.
I also need to change the intake air temp sensor as this keeps flashing up as low signal.

[towcestervag]

the crank posistion sensor is down the n/s of engine towards the rear can be accessed by removing the undertray and looking up behind subframe
if you have got immobilizer codes still it will probably be the immobilizer
try adaption channel 00 erase learned values first if the wiring at key barrel ok

[AutoRen]

Thanks for that.
I have checked the (00) adaption channel and there are no codes present ?
Wiring at the key barrel appears sound.
Will inspect CPS for oil contamination as the engine has a major oil leak somewhere on the N/s.

[AutoRen]

Just to let you know managed to access CPS from above after removing 3 screws from header tank and moving aside.
Found oily contaminated CPS fitted new, fitted new air intake sensor still no joy !!
clutching at straws now.
Next job remove all spark plugs as I'm pretty sure they are drowned in oil due to leaky rocker covers.

If I clear the 17978 code, crank engine with immobilizer key symbol lamp out it is trying to fire but not enough to run. rescan and 17978 is not present.