Ford Fiesta 2009 Intermittent start

[JoshM12]

Hi posted a couple of weeks ago about a really strange and frustrating problem with my 2009 ford fiesta 1.6 diesel tdci. I have since taken to ford and auto electrician with no luck of solving the issue and am in desperate need of help to get an answer to why my fiesta starts intermittently. Any help would be much appreciated.

I have narrowed down the issue to that of the immobiliser flashing rapidly causes the car not to start, the car does this intermittently and always starts first time when i go out to it in the morning or the first drive of the day after that it will play up and start intermittently maybe after 8 attempts of turning the key back and forth. I was told by for that it was the ECU and will cost 1600 quid to repair but find that hard to believe and them trying to rob me of my money. I feel the answer to my problem is simple and has to be to do with this immobiliser flashing rapidly and causing the car not to start. Any help would really be appreciated. Thanks in advance 

[Tdci-Peter]

18 hours ago, JoshM12 said:

I have narrowed down the issue to that of the immobiliser flashing rapidly causes the car not to start,

The immobiliser light actually flashes out a code, google "PATS flash codes".

After a while of steady flashing, it goes to a different pattern, fo example one flash, pause, 6 flashes and repeat, would be code 16.

Code 16 is usually a communications (wiring or joints) problem, for example. Other codes relate to unrecognised or partially recognised keys.

A good diagnostic system like Forscan can also read error messages related to PATS.

The intermittent nature suggests a wiring or connection problem more than a hardware fault in the ECU. Flash codes & DTCs may help narrow it down a bit. It still sounds heat sensitive. Any progress there?

The ECU may be the primary unit that handles the immobiliser. On the Focus, the PATS sensor coil (just round the ignition barrel) goes to the Instrument Cluster, which then communicates with the ECU over the CAN bus. Hence wiring faults can be common.

If you have a spare key, try that. Or try contacting a good Auto locksmith, if there is one anywhere near.

[JoshM12]

On 02/12/2016 at 6:49 PM, Tdci-Peter said:

The immobiliser light actually flashes out a code, google "PATS flash codes".

If you have a spare key, try that. Or try contacting a good Auto locksmith, if there is one anywhere near.

Ok thanks for that advice i will try that next time the immobiliser light flashes rapidly, hopefully it can point me in the right direction for a fix for my car.

I have also tried what you recommended in regards to cooling, I've left the bonnet open and cooled for 20 minutes and still didn't start.

I have also released that i do a lot of town and city driving a lot of stop start and slow speeds after stopping and parking my car in this situation coming back to it it wont start first time but after a few attempts it will eventually. However once i have taken it on the motorway and giving it a good run the problem doesn't happen for about a week before coming back. 

Do you think this could have any effect on issue??

Thanks for your help

 

[Tdci-Peter]

2 hours ago, JoshM12 said:

once i have taken it on the motorway and giving it a good run the problem doesn't happen for about a week before coming back. 

Not related to damp weather is it?

It is just that short heating & cooling cycles can cause condensation, possibly in the ECU or in the Instrument Cluster, or wiring or connectors. A longer hot run would dry things out nicely.

[iantt]

does the engine turn over but not start? or not turn over?

[JoshM12]

I don't think it related to damp weather as it has been doing it since the summer, but could be what your saying in regards to the condensation. Its a difficult and frustrating problem.

Thanks for your help

8 hours ago, iantt said:

does the engine turn over but not start? or not turn over?

And the engine will start first time when you first go out in the day to drive it but once parked and come back to it trying to start it is completely dead, engine doesn't even attempt to turn over maybe after 8-20 attempts of turning the key it will start. 

[JoshM12]

Thanks for your help guys really appreciate it. 

I went out for a drive this morning and started fine as usually once parked and left for about 10 mins and cam back immobiliser was flashing and car wouldn't start. Done what you told be to do to read the pat and the code the immobiliser gave me was 16 so thank you very much for your help. I have done some research and seen its due to a faulty link between the immobiliser module and the ECU most commonly a wiring fault. I am going to get someone to look at it this week and hopefully will be able to fix. Thanks for your help, hopefully saved me a fair bit of money :) 

[iantt]

did you try the spare key also?

[JoshM12]

Yeah i have tried the spare key the issue happens with both keys