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Automotive section => Immobilisers => Topic started by: Tmg on March 05, 2008,17:39:09

Title: Volvo s40
Post by: Tmg on March 05, 2008,17:39:09

1998 Volvo s40
immobiliser problem ? sounds like wont recognise the key (standard chip type key    tried both keys) intermittent will start, But when wont start the EML will flash and stay on also LED on dash will not flash.
any more suggestions
thanks.

Title: Re: Volvo s40
Post by: delambo on March 06, 2008,19:28:53

If it has a transponder immobiliser system then it sounds like the problem could be a high resistance in the reader coil (around the ignition barrel).  From memory though I think the immobiliser is linked to the remote central locking.

Volvos are notriosly difficult to bypass the immobiliser on so it is generally easier to repair the fault.

I will upload a simple circuit you can build in a few minutes for a few quid (a max232, a few smoothing caps, a couple of resistors, a diode or two and a couple of bc547 transistors) that will read the fault codes from the immobiliser and angine ECU's when used with some software I have.

In the mean time however it might be wirth scoping your crankshaft and camshaft sensors (whilt cranking when it is not running).  You are looking for a good strong sine wave with a regular break due to the missing tooth on the reluctor ring.

Title: Re: Volvo s40
Post by: Tmg on March 07, 2008,17:10:39

Hi thanks for any wiring diagrams you have, and the code reader circuit would be a big help. The car only has keys no remote, when it is in not starting mode ( eml lights flashing the car will not turn over at all.
it may start normally 10 or more times in a row and then without removing the key the next time the eml lights will stay on and start flashing then you know the car will not turn over on the starter.
You say about the aerial around the barrel mine measures 3 Ohms

Title: Re: Volvo s40
Post by: delambo on March 08, 2008,17:34:44

Here is the schematic for the interface for fault code reading.

There are loads of Volvo wiring diagrams at http://www.volvo.techno.org.pl/wiring-diagrams.html I also have some more if you cannot see what you want.

As for the resistance, I cant remember exactly what it should be off the top of my head, but I am sure it is supposed to be more like 3K - but I will check and let you know soon.

The software you will need is on my laptop which I will not boot up until Monday now so I will send it then.

Title: Re: Volvo s40
Post by: Tmg on March 08, 2008,19:12:11

Thanks the website is most helpful
any other websites, also have a problem with Alfa gta HID lights