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Discussion Starter #1
I am having a real problem with my Astra at the moment. Its a Mk4 1.6 16v SXi Z16XE engine and it has been running fine until a few weeks ago.
I've spent the last 2 weeks replacing things on it to try and sort out the problem but it is still the same as before.

The car will start from cold first time every time, no hesitation, no stuttering or any problems at all. As soon as it gets to about 85-90 degrees it will cut out, not splutter and die, just cut as if I turned the engine off with the key.

So far I've replaced the fuel pump relay, fuel pump, fuel filter, and coil pack. Last night I tried a different crank sensor in it (pulled from a scrappy) but the problem still persists and is easily replicated each time I try and fix the car now.
If anyone could offer any advice as to how I could solve this problem I would be eternally greatful right now as I'm stuck without my car and its already approaching the 3 week mark now.

Best regards.
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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Have the fault codes been read?

Diagnostics with TECH2 or other tool could watch the data from the sensors and see what happens when it reaches the point where it cuts out, and then does not restart.

Does the engine management light come on with the ignition as normal when you try to start the car when it has failed?

Could be an internal fault in the ECU - being mounted on the engine they get hot, which can cause failure. There are companies out there that can repair them. Unfortunately, you can't just get hold of a second-hand ECU and fit it to your car. The old one must be divorced from the immobiliser, then the replacement one programmed back in.
 

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Discussion Starter #3
Thanks for your respone.
I have an OBD2 plugin which I am using to read the fault codes. When the engine cuts out I get a p0230 which is Fuel Pump Primary Circuit Malfunction.
Having googled around it seems that it may not be the fuel pump/relays that are to fault here and that other things could be causing it to 'malfunction'.

I had read that some people had the same issue and changing the crank sensor cured the problem, however for me this is not the case.
I have already read about ECU problems and I am leaning towards this as the cause now as I cannot see what else I can try to find out. Can I not get an ECU from a scrappy to test, regardless of the security codes from the immobiliser? Even if it's just to see if the car will run with another ECU in it.
Failing that I have found a company which can test and repair them and I am awaiting a call back on a price for this service.

Do you know what hardware/software would be required to reprogram an ECU for my car as I would rather do this myself if possible and have the tools to do this in the future than pay the garage a ridiculous amount to do it once and find that it isn't the problem.

Kind Regards.
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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Thanks for your respone.
I have an OBD2 plugin which I am using to read the fault codes. When the engine cuts out I get a p0230 which is Fuel Pump Primary Circuit Malfunction.
Having googled around it seems that it may not be the fuel pump/relays that are to fault here and that other things could be causing it to 'malfunction'.

I had read that some people had the same issue and changing the crank sensor cured the problem, however for me this is not the case.
I have already read about ECU problems and I am leaning towards this as the cause now as I cannot see what else I can try to find out. Can I not get an ECU from a scrappy to test, regardless of the security codes from the immobiliser? Even if it's just to see if the car will run with another ECU in it.
Failing that I have found a company which can test and repair them and I am awaiting a call back on a price for this service.
As I said, you can't just get hold of another ECU a fit it without a bit of programming work. If you fit another ECU, the immobiliser will not be matched to the ECU and the engine will not start - all you will get is a flashing engine management light. The only possibility is to obtain the immobiliser and transponder chips that are matched to the donor ECU, and fit all those parts to your car at the same time as the 'test' ECU.

Do you know what hardware/software would be required to reprogram an ECU for my car as I would rather do this myself if possible and have the tools to do this in the future than pay the garage a ridiculous amount to do it once and find that it isn't the problem.

Kind Regards.
If you just want to divorce and program ECU's into your vehicle, you will need a piece of software called Vaux-Com or Op-Com - cost about £800. Beware of the cheap versions doing the rounds on eBay that are pirated copies of the real thing, and are often early versions of the software with bugs, limited features and no support from the developer in case of problems.

If you want to have all the capabilities of a Vx dealer, then you need a TECH2 machine, which is about £4000, and includes the facility to load new firmware into the ECU's. If you bought a new ECU from a dealer, they are supplied blank and require programming before they can be used.
 

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Discussion Starter #5
Well firstly, you seem to know your stuff!
I am tempted to get the whole lot from a donor car just to test it. It seems in some ways easier and definately cheaper than getting new parts.

Failing the ECU tests, what else can I check? Like what other sensors relate to the fault that I'm getting? The only things I've read is fuel pump, relays, wiring and crank sensor. I'm wondering if theres anything else I can try before trying the ECU?

I am also tempted to wire an outside loom for the fuel pump to see if there is any problem with the wiring there. This would be right from the relays all the way through to the fuel pump itself.
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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Worked on the good old Astra-G for a few years, so know a fair bit about about them! ;)

Usual cause of engine cutting out when it gets hot is due to the crank sensor, but you have ruled that one out, plus you wouldn't get the P0230 code.

This code is pointing to either a wiring fault to the fuel pump relay, or between the relay and the ECU, or the ECU itself.

The P0230 code comes up because the ECU knows it is getting a good supply from another relay, and it detects the loss of supply to the fuel pump/injectors, knowing it hasn't switched off the fuel pump relay.

To hopefully prove it's the ECU, you could remove the brown/green wire from the fuel pump relay terminal 6, then install a temporary earth wire. This will make the pump run all the time the ignition is on, and cause another P0230 code to be stored in the ECU (Fuel relay voltage low), but the engine will still run when it gets hot - if the ECU is the problem. ;)
 

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Discussion Starter #7
Loving the help from you dude. Really appreciate it.
I've found something interesting while messing about with my car this evening.

After the car hits 90 degrees (approx - 94c from my OBD2 plugin) and cuts out. My friend poured cold water over the ECU (about 4 pints, it was out of a milk carton!) After that, I started the engine first time. I cut the engine then restarted again and it worked again.
This points to the ECU overheating? Possibly part of its circuits are shorting or something, could be as you said, something to do with the return from the relay on the fuel pump.

Due to my curiosity getting the better of me I then decided to remove my ECU and open it up, whats the worst that could happen? It's already broken! Kind of pointless though as its gell filled and you can't touch the circuit board.
One thing I did notice is that not all the components on the board are covered in the gell. I'm presuming this gell acts as some kind of thermal gell to disipate the heat off the circuit and onto the heatsink. Could it be that this gell has some how disolved/evapourated and is not providing enough contact to cool certain compents?

I hope I'm not bogging you down and babbling on, just kind of venting after playing with my car!

Regards
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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That was a good idea with the water - didn't think of that. ;)

I think you have proved it is the ECU that is the culprit. What happens is one of the many solder joints that secure the components to the board can develop a minute crack due to heat cycling and vibration. The join is OK when cold, but as it heats up it expands, the crack opens up and breaks the circuit - car then stops! If you have a look at this post ( http://www.astraownersnetwork.co.uk/showthread.php?t=113076 ), someone has found a similar problem on ECU's from the 1.7 Diesel engine, and shown how to repair them.

The gel is a form of potting compound - used to encapsulate the components to protect from heat, vibration and moisture. It can be removed if you either have patience, or access to the right chemicals.

There are companies out there that can repair your ECU, which will mean it will not have to be re-programmed when refitted, unlike if you get a new or second-hand replacement.
 

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Discussion Starter #9
Just so you know, I found a pic of what my ECU looks like.


I have been reading around about 'potting' and how to remove it and it sounds very hard and quite possibly dangerous due to the way the ECU is soldered. Apparently it is hardwired into the heatsink/metal casing and to get it out, or to see the flip side of the board where a possible problem could lie would mean de-soldering something like 100 points.

Gonna see what happens at the scrappy tomorrow and hopefully get all the required parts from an 'LS' mk4. The engine 'looks' the same as mine so I'm hoping the ECU will be ok. Do you think that the map on the ECU will be different or will it work ok?
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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If it's the same engine, and approximately the same year as your car, then it should work OK. It may be best, once the new parts are fitted, to get the software version of the new ECU checked to ensure it matches what should be installed. There is a small chance that the wrong software could cause engine damage in the long term.
 

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Discussion Starter #11
I have a program for OBD2 that shows me software version for my current ECU so I will compare that with the donar ECU and hopefully it wont be different. I'll let you know how I get on with the new ECU. Hopefully my problem will be cured.
 

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Discussion Starter #12
Right then. New (scrappy) ECU fitted with immob and chip. Engine starts and runs nicely. Bit lumpy to begin with but smoothed out quickly. I do, however, have more faults coming up :(

P1120 Throttle Position Sensor/MAP sensor - implausible signal
Accelerator pedal sensor A - circuit malfunction
P1122 Accelerator pedal sensor B - circuit malfunction
Throttle position sensor - supply voltage low
P1550 Electronic throttle system - in emergency mode.

I haven't driven it, just idled and gave it some throttle. I can feel that the accelerator pedal is 'limp' as it's got a lot of travel before it kicks in.

I checked the details on this new ECU and it says 'Software Version Number 10' where as my original says '5'. Other than that, the information is almost identical apart from the GM ECU Software number which is DPAB on this new one and DJTX on my old one.

If you or anyone else could help with this I would really appreciate it.
One a side note, the engine does not cut out when it gets hot anymore, but the car is still useless as it stands with these faults due to limp mode kicking in.
I tried the water trick again but it made no difference.

Regards
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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If the part number of the ECU is identical, then it looks like the difference lies with the software contained within. Getting the new ECU flashed to the correct version according to the VIN number on your car should sort the problem.

The other possibility if flashing new software makes no difference is that they changed the pin configuration between the models, so the pin that supplies power to the throttle position sensor (hence the supply voltage low fault) is different. This would mean either changing your existing loom to match the new ECU, or getting and fitting the engine loom from the donor vehicle.
 

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Discussion Starter #14
How much am I looking to get it flashed? I've already paid out enough as it is!
The part number is identical to my original. The only difference is the software version number and the GM version number (the DJTX on mine and DPAB on new).

I have a feeling that if I go ahead and get it flashed it will come back as the fuel pump relay fault again! Probably faulty wiring <_<

Thanks again for your help.
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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Vauxhall probably charge the best part of 1 hours labour to reflash the ECU - average labour rate is £70 per hour +VAT.

As you are in the West Midlands, there is an approved trader on here called Pecky who I *think* has the ability to upload new firmware. He lives in the West Midlands area. His prices will be a lot less than Vauxhall! Try sending him a message to see if he can help you out - check out his website at www.diagnostics.org.uk
 

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Discussion Starter #16
Thanks for the info, I've checked that guys site and he's not far from my parents house. I will be there next week so I might take my ECU to him to get it flashed and see what happens.
Been playing with the car again tonight, tried a new accelerator pedal but i'm still getting the code from the new ECU. I noticed that there is a high pitched whining noise coming from the throttle body, I'm guessing its the motor for the butterfly valve. Is this normal or should it be silent? It sort of worbles when you press the accelerator pedal with just the ignition on (position 2), without the engine running.
I took it off and cleaned it as best I could but it wasn't really that dirty, just kind of black on the under side but nothing major and definately not enough to stop it from opening/closing correctly.

I'm pulling my hair out now as the engine will run but it just wont come out of limp mode and let me drive the damn thing!
Hopefully some more testing of certain things will help me get closer to a solution.
Thanks again for your help. You seem to be the only person with any knowledge of anything right now!
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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Thanks for the info, I've checked that guys site and he's not far from my parents house. I will be there next week so I might take my ECU to him to get it flashed and see what happens.
Been playing with the car again tonight, tried a new accelerator pedal but i'm still getting the code from the new ECU. I noticed that there is a high pitched whining noise coming from the throttle body, I'm guessing its the motor for the butterfly valve. Is this normal or should it be silent? It sort of worbles when you press the accelerator pedal with just the ignition on (position 2), without the engine running.
I took it off and cleaned it as best I could but it wasn't really that dirty, just kind of black on the under side but nothing major and definately not enough to stop it from opening/closing correctly.

I'm pulling my hair out now as the engine will run but it just wont come out of limp mode and let me drive the damn thing!
Hopefully some more testing of certain things will help me get closer to a solution.
Thanks again for your help. You seem to be the only person with any knowledge of anything right now!
The throttle body motors often make a high pitched noise, but it does sounds as if yours is struggling - almost certainly down to the fault codes stored in the ECU.

If Pecky can flash the ECU, he would need to come to you and program it on the vehicle, I think.
 

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Discussion Starter #18
Just picked up a throttle body so I'll be testing it later tonight after work. Again, I'll let you know how I get on with it.
If this fails I'm probably going to call Pecky and see what he can do for me, I'm about an hour away from where he's located at the moment so I'll see how much travelling he's willing to do.
 

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Discussion Starter #19
So I tried the throttle body the other day and its exactly the same as before. I can only deduce that it is the ECU that is at fault. All this testing and such for nothing I guess.

I will be purchasing a new ECU (remanufatured) from eBay with a 12 month warranty and a return policy should it still not work. These are guaranteed to work though so if it doesn't then I know my car is totally ******!

Once I have the ECU on, I will post again to let people know how it turned out. I was sick of reading threads of similar problems to find that it ended without a resolution so hopefully for the help of others I will keep this as complete as possible.

Once again, thanks to LADmachining for all your help.
 

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A.O.N - Approved Vauxhall Specialist (Anthony)
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No problem, you are welcome.

Hope it all works out OK - I am sure the replacement ECU you have fitted would work OK with a software update.

You will have to have the remanufactured ECU programmed to your existing immobiliser. That means the original, defective ECU will have to be connected back into the car and 'divorced' from the immobiliser ECU before the new ECU can be programmed.

Nothing is ever simple with modern cars!
 
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