Ford Fiesta Studio 2008 Possible Immobilizer issue

[Suze-t]

Hi,
For a few weeks now, my 2008 Ford Fiesta studio wouldn't start first time and the immobilizer light was flashing rapidly. To work around it, I would get out and lock the car, unlock and try again - and most of the time it would start. Or take a couple of relocks then start.
Last week, it got worse and would take several attempts to start, so I booked in with an auto-electrician.
The report and prognosis I got was:
System report w/codes
Engine & Immobilizer PATS

• B1601 PATS received incorrect key code from ignition key
• P0325 Knock sensor 1 circuit malfunction
• P0324 Knock control error
• B1681 PATS transceiver module signal is not received

My technician has advised either a replacement ECU kit as it includes the ignition barrel which is the main part to be replaced. Apparently, Ford no longer make a replacement (and if they did, he guessed £4k to replace) so I would have to source a second hand part for the auto-technician to install. OR installing an emulator to bypass the immobilizer. (and not telling my insurance)

Does this sound like my only 2 options? Ive tried to do some research and it could be a dodgy fuse instead? I'm thinking of getting a second opinion aswell

If it helps, the problem occurs with both keys i have for the car

Any advice would be greatfully received - and nothing too technical as Im not any kind of expert with cars

 

[Handy Andy]

As the process of elimination - you did replace the watch (CR2025) battery in those fobs correct?

Else if the Vehicles own battery has not been replaced - this may indicate a "relearn" process that occurs when the battery standby voltage at the cars own 12V battery - drops. Drops - to a threshold that the PATS system thinks it needs to armed and so therefore even drains the system further until you can get the car started.

You'd also notice certain Audio presets, Sound settings and even some Vehicle settings not working correctly or even the Clock seems to run oddly off (fast or slow) during these times.

That would also indicate a good cleaning of ground points for the electrical system is also needed.

 

[SyntheticAtmosphere]

Did you previously have a "Check engine" light? I am trying to understand if the P0324 & P0325 Knock codes were already a previous issue to the Pats issue. These two codes are unrelated to the Pats, however if they appeared all at once, there are multiple causes for situations like these. If the knock codes are a pre-existing condition, the issue is most likely solely related to the Pats issue.

 

[Suze-t]

As the process of elimination - you did replace the watch (CR2025) battery in those fobs correct?

Else if the Vehicles own battery has not been replaced - this may indicate a "relearn" process that occurs when the battery standby voltage at the cars own 12V battery - drops. Drops - to a threshold that the PATS system thinks it needs to armed and so therefore even drains the system further until you can get the car started.

You'd also notice certain Audio presets, Sound settings and even some Vehicle settings not working correctly or even the Clock seems to run oddly off (fast or slow) during these times.

That would also indicate a good cleaning of ground points for the electrical system is also needed.

Hi, my key isnt a fob key, its just a normal key. I also had a new car battery at the start of this year, months before the problem started.

I've not noticed any other settings not working

 

[Suze-t]

Did you previously have a "Check engine" light? I am trying to understand if the P0324 & P0325 Knock codes were already a previous issue to the Pats issue. These two codes are unrelated to the Pats, however if they appeared all at once, there are multiple causes for situations like these. If the knock codes are a pre-existing condition, the issue is most likely solely related to the Pats issue.

Hi, no lights / warnings - just the no starting

 

[SyntheticAtmosphere]

Hi, no lights / warnings - just the no starting

Did your mechanic mention they were able to experience/re-create the issue, or just pulled the codes?

I am surprised your knock codes havent triggered a CEL (Check engine light) Im leaning towards an issue with your CANBUS. This is a communication protocol where your cars various different systems can talk and understand what each is doing. Perhaps have a mechanic verify the system is working properly and not experiencing anomalies. Right now its just a hunch, you decide if its warranted.

 

[Suze-t]

Did your mechanic mention they were able to experience/re-create the issue, or just pulled the codes?

I am surprised your knock codes havent triggered a CEL (Check engine light) Im leaning towards an issue with your CANBUS. This is a communication protocol where your cars various different systems can talk and understand what each is doing. Perhaps have a mechanic verify the system is working properly and not experiencing anomalies. Right now its just a hunch, you decide if its warranted.

Hi, yes i took it to an auto electrician who confirmed they had the same issue and it got worse whilst they had it

 

[Suze-t]

On another forum, a faulty instrument cluster has been suggested...

Its stressing me as I dont know if the auto electrician has told me correct info, and as I now can't find a suitable replacement ECU kit, my option is a Immo Emulator (which god knows what that will do to my insurance) or getting a second opinion if I can get the car started....or get a new car

 

[Handy Andy]

When you have an older car, many Gremlins that show up are due to the failed defenses of wiring, components and or a combination of both...Broken wires, onto poor contact or corroded convectors onto bad components caused by power spikes in the electrical system - can cause conditions like this.

The problem was "solved" by adding other elements to reduce the drying out condition
as well as breakdowns - Galvanic and Electrolytic actions that destroyed their plates.
An article based upon the above definition including it's own history
- here at Wikipedia.​

• The condition may have occurred in your own vehicle. Due to development and reserve of parts to build the modules.
• We, you or anyone - cannot determine that, until you tear down these electronic systems and inspect them to determine the age of these components and if they were part of this problem.

​

The vehicle is a 2008, so I can only presume that although taken the utmost care of, you cannot get away with the impossible being that it was designed to last forever.

Age of the electronics are show up in various ways. Including the failure of systems - they just don't work anymore - why? Failed or dried out capacitors that are designed to filter, smooth out or detect - power supply feeds and the other systems that rely on this can quit working too - can affect operation - as similar to minor quirks becoming cascaded failures.

• That is just one cause of a condition - there are many other ones we haven't even considered.
• Age, being both wiring and connections - Copper in it's refined form - does go thru a process of reduction so corrosion of the wiring is inevitable. The jacket composition can be of two types - a plastic or a soy-based polymer - both have a finite lifespan.
• Connectors - their plating is not infallible to moisture water and or salts and minerals that contaminate the contact points.
• Bolts; hold the vehicle together, used to provide ground points - hold seats down - keep the strut and springs from falling out - all will rust and weaken.

The problem also lies in the ability to find spare parts for such a limited edition vehicle - which in order to preserve the vehicle you have to tear down the systems and inspect wiring and fix the many intricacies of the wiring connection points and components used - to ensure the continued operation of their systems.

Now, whether this happened in your vehicle is hard to determine without your electricians working their "magic" in isolating or even probing to find problems what seems to be akin to intermittent connections caused by the wiring failures.

 

[Handy Andy]

Here are some other thoughts on this.

Since you've said your car has PATS - that means the key you have in your hand - also has a chip in it to identify itself to the PATS system.

So if there is a chip in it - it needs a battery to power it - to emit the signal to tell PATS what it is and PATS determines to allow access to start or immobilize the system.

But there are other factors to add to that - as both a diagnostic check of the the PATS health as well as the ability for you to even enter the vehicle without having a chip in your key - or you have a key with a dead battery so it has no way of knowing what or how or who your are - doing in the drivers seat - that's the PATS system, it relies on a set of "steps" taken by someone as they gain access to a vehicle - the right way - to know whether they pass-in or have no access to the system.

So if you have a key, try the door lock - turn the key once to open that door, or twice in succession to open ALL doors - if it passes that test - the PATS system usually doesn't care because the throw of the tumblers key-switch - is enough "proof" for someone to enter in.

Why does that work?

The Door lock itself uses a mechanical lever to operate an electric switch to bounce it's contacts and tell the PATS system to "Wake up" - we're getting in.

Well if you're a thief, many steps can be used to mask the intrusion but mostly by fooling the system into thinking your something else - so when someone attempts to open the hood to disable the battery or gain entry thru the trunk without the system detecting any sort of ID from the key or any form of entry - PATS immobilizes the starting system to prevent starting - but it's not perfect. It won't sound an alarm until a threshold of noise level is reached nor will it sound the alarm if the doors are unlocked or it thinks they are unlocked. But opening the Hood while the system is armed is a very blatant attempt to gain access so it can and does sound an alarm if it's programmed to do so.

So with you having issues - did you ever try to see if there is a "sounder unit" in the vehicle - it would be part of that PATS system and gives you a battery charge level indicator on certain specific start up conditions - in a display on the instrument panel to let to know of the condition of the battery in it's alarm sounder system. That battery is important - so that if the main battery is pulled - the alarm still has power to sound off.

This sounds like you have a sounder unit - and the Alarm unit in it has a dead battery or it's quit functioning so the PATS system does an integrity check called a Loop-back that checks for the Alarm to exist and if it works. The system (PATS) clears the condition and then lets you start the car and drive if it's there and works. But if the Alarm sounder unit is bad, that can make the PATS system see a fail in the loopback test and immobilize the car from starting.

So check - run your VIN and see if PATS has a sounder unit for the vehicle - these units are located by the front RIGHT strut in an alcove behind it so you hear the sounder and the bolts to hold the on unit are on the struts inner tower towards the top where the strut mount rests.

Due to the nature of the vehicle and it's age - that sounder can fail and prevent you from starting your vehicle because the PATS system can not verify it's integrity.

 

[Suze-t]

Thank-you all for the helpful replies - ive now taken my car to a different auto electrician and its fixed!! the issue got worse since the first post and I realised it wasnt the immobiliser. Final diagnosis - it was the ignition switch