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I still can't read the PCM (I brought a cheap-ish OBD2 Scanner) but i don't know what's stopping me reading codes? Is it the cluster or ecu?
I do kind remember months ago when I started the car I had no power steering, but a quick restart fixed that, and it's been fine until this issue, so I never gave it a second thought.
Today I went to check the cables in the engine bay and noticed my battery is flat.....seriously WTF !!! I hope i don't have a parasite.
That may need a proper investigation by a trusted mechanic/auto electrician. Hope you find it soon. Nothing worse than not being able to diagnose a fault.
 

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Discussion Starter · #23 ·
You have a bad ground or power issue at ecu.

The intermittent functionality of the ecu its the key. The red light will flash whenever the ecu is unresponsive.

How long it passed since the rebuild/last had the car at a garage for engine work ?
I take the car back to them yearly for its MOT and servicing.

The last time I had an issue was around 2 years ago when I thought my head gasket was broken when the car's engine started stuttering and white exhaust smoke.
So got the car transported to pumabuild and Alan found the problem, it was the intake manifold gasket and what a state it was.


As a side note, I've been trying to tell Alan that when I tried to overtake in 6th gear, the engine stuttered and cut out. After restarting the car, everything was ok.
I've also noticed when I put my foot down in any gear at lets say 4000 revs my boost gauge goes to maximum but the engine judders. If I take it easy, everything's ok.
When I keep telling Alan he gets a staff member to drive the car but never gets this problem so I suppose there's nothing to fix.
 

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Discussion Starter · #24 ·
You have a bad ground or power issue at ecu.

The intermittent functionality of the ecu its the key. The red light will flash whenever the ecu is unresponsive.

How long it passed since the rebuild/last had the car at a garage for engine work ?
Oops! Forgot about ground issue.
My car has an upgraded ice system fitted my a proper ice installers, there's a huge black cable connected to the batteries negative terminal and the other side of the cable is bolted in the engine bay which looks like the bolt was connected to a drill hole.
If needed, I'd be happy to take a few photos?
 

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Discussion Starter · #25 ·
That may need a proper investigation by a trusted mechanic/auto electrician. Hope you find it soon. Nothing worse than not being able to diagnose a fault.
I recently lost my job thanks to everyone cutting back, so I don't have the money for this.
I could only do little bits like cluster repair etc
 

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The alternators a common issue and when it does go it usually fries the battery also. Symptoms sound very similar to what I had, the car ran for a while then absolutely nothing at all, and it was because the car was running using the power of the battery alone, once it drained it was game over.
The other thing to note is that the battery’s been tested for voltage, but that doesn’t mean it’s alright, if it’s not pushing that current out to the rest of the car then nothings going to work. If the battery/alternator aren’t functioning properly then you won’t get any readings from the ecu/pcm/nothing.
 

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Discussion Starter · #30 ·
If it is an ECU problem I can recommend these guys. They sorted out the ECU on my old car when it went pop. They can test it as well for peace of mind but it was only a couple of hundred pounds to replace with new & they even copied across my maps etc. Couple of days & I was all sorted.

https://the-ecu-doctor.co.uk/
This is awesome, thank you so much.
I really don't want to give anything to Alan because I'd probably not get my ecu back until summer !!

I remember pumabuild telling me it's a rs ecu and I hope that's not going to be a problem??

By any chance, do you know what could've caused the ecu to just half work?
I say half work because when the engine starts it sounds normal
 

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Discussion Starter · #31 ·
Guess I was lied to !!! It's not an RS ECU, it's the normal ST.

I'm confused to how the engine starts, it sounds normal when it does start??

i wonder if it is in fact the ecu ?
 

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Does anyone know why the engine runs fine with the ecu being broken ??
It costs a lot to clone etc. so I'm trying to figure out if it is the ecu that's faulty
If you send the ECU away to a reputable company they will normally do a full diagnostic for a reasonable price then let you decide on a full repair.

What did autotronics say in their report regarding the cluster repair?
 

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Discussion Starter · #36 ·
If you send the ECU away to a reputable company they will normally do a full diagnostic for a reasonable price then let you decide on a full repair.

What did autotronics say in their report regarding the cluster repair?
I was hoping someone knew my question about the engine running fine with this ecu because I could've saved money testing.

Yes, autotronics told me that there are no faults.
I just emailed them and asked if there's a report on the tests etc. so I'm waiting now.

I rang around earlier for quotes on the ecu, and in the end I chose pumabuild because it's so much cheaper, and they have experience on my car.
Not only that, but I wish I could've found cheaper places because ill probably get my ecu back in summer !!!

I can't wrap my head around how or what caused the ecu to stop working whilst driving, I mean its water tight and cool.
Hummm I wonder if the cables were just loose? I might plug it back tomorrow and see what happens?
 

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As I understand it it is essentially a hard drive/"simple" computer. It might just have glitched, failed, corrupted, poor connection...

My pc won't turn on if I leave something plugged into a specific usb port. Wouldn't be surprised if the car won't start or tries to protect the engine if it's not getting a clean signal through a certain pin...

If you've ruled out battery (and it's connected properly, I don't fully understand how but I've had a car that would sometimes start sometimes do nothing and it was simply because a battery connection was a little loose...) And the clocks definitely aren't at fault and the wiring isn't damaged and you've been told it's most likely the ECU, it's probably a good bet to have it tested as a likely culprit
 

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My old 500 would start fine sometimes & run okay before suddenly cutting out. Other times it wouldn't start up at all. Lastly some times it would start & run like a bag of spanners. All completely random. When the ECU Doctor took my ECU & tested it they said it was not an uncommon issue on the ST ECU's - especially if they have been moved to make way for a CAIS or similar - like mine had. What happens is that the pins & connections on the main board in the ECU get brittle, break, and start making intermittent contacts though heat (if in the OEM position), or heat & being pulled about (if put behind the headlight). Hence everything looks fine from the outside but the signals are corrupted internally. Consequently the ECU goes haywire randomly. As stated in my earlier post they opened up my ECU & put a new board in it remaking all the pin connections & it was sound after that.
 

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Previous post is what I was told by the company that repaired my Instrument Cluster. I had similar problems to the OP and my Instrument Cluster was the problem. Cracked solder loses a solid connection with the ECU, ABS, Power Steering, Throttle and Accelerator sensors, Immobiliser which cause dash lines, limp home mode, car cutting out, immobiliser faults etc. Could start the next day then cut out and not start again. Cheapest fix first, fully charge the battery, test the alternator and cluster repair for preventative maintenance.

I think I saw a post on the RSOC about a parasitic battery drain, which turned out the be the keyless sensor module. It was on its way out, draining the battery, causing all sorts of problems, as the car was losing signal with the key and it would just cut out.
 
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