Technical HELP!! Intermittent Immobiliser problem!!

[peculiarfish0]

Hi Guys

First time poster / Fiat owner

So, I have a few Issues with this car, that may or may not be related!

Firstly the major one.

Sometimes, the Immobiliser won't turn off, and the car won't start
(Immob light stays on the dash)

However sometimes it works fine.. I had to get it towed home last week though as it wouldn't start and I was in a pay space. So this has now cost me £80 already.. and I'm not using the car (even though it started the following day)
as I don't trust it.

I only have one black fob Key.
AA guy said probably faulty chip in the key, But vehicle Locksmith guy said it's most likely not the key, as they tend to either work or not.
£140 for new fob/Key. But not sure what to do now...


Secondly. most of the time (when it worked) when starting the car for the first time, The power steering didn't come on. Had to turn the engine off and restart, it would always come on the second time round, and worked fine.

Thirdly. The 'Check Airbag' notice sometimes comes up across the screen,
I can't remember if it stayed on the whole time but I think it just popped up every now and again.

Thats all..

Thank you very much for any help given, I need to get this worked out but don't have any money to pay someone and my usual mate had a stroke recently so I'm on my own with this one!

Any way to check what is causing the immob problem for sure?
As it is intermittent sometimes it works fine, I wont know if I fixed it or not?! lol

 

[Bernievarian]

Hi and welcome on board,

as already developped many times in this (and other) forum, weird / intermitent electrical fault involving steering wheel assist, ABS, immobilizer etc. are most of the time related to either a bad grounding or a weak battery...

Once again:

the cable that connects the battery to the car's body is prone to convert to dust, one wouldn't see anything since this lead is insulated but as its functionnal section shrinks, the voltage drop on it goes higher to finally get so high that the remaining voltage is too low to operate the electronics properly...

There is a method to check this in the top section of this forum.

BRs, Bernie

If someone here helped You understand ,or better, fix your issue, hit the thanks button @ bottom right corner, it's free and make us feel helpy

 

[peculiarfish0]

Thanks for the quick reply, I had a look at the 'Electrical Gremlin' thread.

I checked the battery terminals and the Grounding points.
They all look fine, no corrosion, I cleaned up and put Vaseline on the battery terminals anyway.

(Bare in mind the car started fine last night)

But now once again the immobiliser light won't turn off, so no start

Shall I get a new key done just to clear that off the list? (£140)
or Is there cheaper things to try first?
how about this reader that goes around the ignition?

Cheers!

 

[aurick86]

The ground cable can look 100% new and it can still be 100% faulty.
(as Bernie said, the cable goes bad inside.. )
I know that from first hand experience.
A multimeter is not the correct tool to test this. you need a big consumer.. like a starter motor pushing the car.

Another thing to try is to move the steering wheel in all possible directions .. up down, in, out. etc.
You can also unplug and clean the ECU connectors (use a electrical contact spray), the body computer connectors.. etc.

 

[peculiarfish0]

Also I did the second set of tests in that thread,
putting the jump leads on negative battery terminal
and then connecting to the engine or chassis on the other side by the belts.

Same thing happening, ignition on, but immobiliser light stays on..

Does that bypass the negative battery earth cable? So its not that then?

Thanks

 

[Lokie]

I see you say you only have one black fob key (i.e. the one your using)

Another alternative is to buy a complete lock set off a fiat breaker (around £80) look on ebay, will come with at least one key but sometimes you can get with two, you swap the set with your old ones (but if you can get a new key at £140 thats cheap for a fiat, after checking above items if still no joy I think I would just get a new key done for £140

be aware though; Keyfax (who a lot of dealers use in Northwest UK) told me few weeks back that some Fiats (Grande Punto 199s) are dearer ( example Ford key full remote is £120, manual is £80) Fiat though they tell me at moment is silly money but they are working on a fix or cheaper option?? This because I have a remote key on daughters punto which will not cancel immobilizer (is faulty transponder) when inserted into the key coder (with keyfax tech) it is US.

I am debating whether to split the manual key, remove transponder and fix to steering ring under column cowling that receives signal from transponder this then means can use a blind key which can buy off the bay for £23 then just get blade cut from key code.