Engine ECU

[Damo]

Guys, has anyone ever replaced the engine ECU in their car if so have you any instructions for doing so or recommend the best place to buy one?. I reckon I must have damaged the ECU that time I tried jump starting the ladies jeep. My car just flew the NCT, I have no Sensor errors showing up but I still just don’t have any kind of power so I am down to the ECU now. Any info appreciated?

[CJ]

Damo, it should be pretty straighforward -

1. Remove the passanger side kick plate
2. Locate ECU and disconnect the 4 sets of plugs
3. The ECU is bolted to the chassis, unscrew it.
4. Reverse the above order and drop the new ECU in place

Steelroe, RicerocketUK at al should be able to assist in terms of supply.

CJ

[Damo]

Thanks for that CJ

[prestigejs]

Hi, before you purchase another ECU, have you tried changing the ignition failure sensor located on the right hand side of the engine, (small flat sensor about half way down with a metal base held in with two screws). This often blows and will cut power to the ECU and fuel pump, leaving you with no spark, hence the car will not fire.

Common Problem.

Nick.

www.mitsubishi-fto.co.uk

[Damo]

quote="prestigejs"]Hi, before you purchase another ECU, have you tried changing the ignition failure sensor located on the right hand side of the engine,

Nick,
No i didn't try that, but I have already changed the Cam and crank sensors, I have since had this car at the Mitsubishi garage and with a diagnostics guy and its not showing any more sensor errors wouldn't this ignition sensor show up on the MUT II? any other advice or ideas would be most welcome because the car has only really driven properly for about 3 months of the 12 I've had it. I'm thinking I probably damaged the ECU because a while back I tried jumpstarting somebody's car and I blew a load of fuses.

Thanks,
Damo.

[prestigejs]

It wouldn't alwas show unless the car is running as it is more of a pick up sensor, normally if it is an ECU fault the diagnostics won't connect with the ECU.
The idea of this sensor is it reads the signals and then sends them out from there, if this is not working then the first thing you will lose is the spark and then possible the fuel pump, which you can check when you switch the ignition on. The only other possibility which you may well have blown is the relay which is situated in the centre of the dashboard on the left hand side under where the stereo sits, which is very possible. I would suggest checking that first now you have mentioned blowing the fuses.

Have you checked the large capped black and brown fuses in the fuse box to make sure they are okay.

If you find you need any of these parts we also have them in stock, but i would go with the relay and then the sensor first.

[Damo]

Nick, I looked yesterday for the relay but couldn't find it. Can you tell me where exactly it is? Thanks a lot.

[prestigejs]

Ok, the relay is a gold colour and on a tiptronic sits just in front of the gearbox ECU.
If you carefully remove the centre ski slope or the passenger side centre consul side panel you will see the relay sitting on the left hand side bolted to the thin grey coloured metal frame at the bottom which runs down at an angle. The side panel is normally screwed into this frame.
Hope that helps.

Nick.

[Damo]

Thanks I'll have a go again. Mine's a manual though any difference?

[prestigejs]

No relay should be in the same place near the front.

[Autofix]

Hi,

If the ignition sensor was not working would there not be misfire codes or an ign primary open circuit (p0351) code.

The relay you mention. If this was not working then surely there would be some part missing a supply and so not working?

Does this car not have a factory immobiliser? If so then a replacement ECU will not be plug and play as it will need matching.

HTH

[Damo]

Hi Alan,
I had this car down with you (white FTO), its still driving like crap I'm just clutching at straws really. It didn't come with an immobilser installed, I just got one fitted the same day I was down with you actually. It's like driving an old Diesel car is the best way i can describe it.

[prestigejs]

Not always on the FTO, if the ECU has been reset then it wont always bring up a code until the car has run, this relay is a power relay that has two functions one of them also controls and powers up the fuel pump.

The first thing i would do is crack the nut on the fuel pipe slightly if you are doing this yourself and get someone to switch the ignition on and back off to make sure there is fuel coming through, it will also tell you if the pump is getting power. It will be a quick way for you to check if you don't have the relevant equipment.

A lot of costly problems that people pay normal garages to solve on the FTO is simply just this relay, but garages don't check and look for other reasons there is no spark, The relay send the correct signals and in turn fires up the fuel pump in turn the car fires. Without this it does neither.

Without looking at it i could be wrong but it is always the best place to start when there is no signal or spark.

[Autofix]

Hi,

Damo, yes, I remember. If I recall correctly when you were in with me your car behaved itself. I think we just code read it and watched live data on the road but since the fault was not there we could not see anything. Has it being playing up all the time since then? Give me a call if you want to have a chat about it.


prestigejs. The relay you refer to is a fuel pump relay (must be if it powers the pump). I do not have a diagram handy to look at but I am pretty certain that it will also power injector supply, egr etc. If this relay fails the pump will not run. Since this car is running then the relay could not have failed completely. It is possible that the relay could be supplying a reduced voltage and so cause running concerns. This could be eliminated very quickly by supplying a fused supply directly from the battery to the output (T87) of the relay, or directly to the supply side of one injector.
You mention that when faulty this relay also causes lack of spark. Does it supply the coil as well as the pump, or does it supply the ECU? It would be a bit unusual for this to be the case. Could this be a main relay rather than a pump relay?

regards

Alan

[Damo]

Alan,
It has been the same since then really, it flew home after being with you but the next morning was back the same again. I'll try suss out this relay and the sensor recommended by Nick if that doesn't sort it maybe I could leave her with you again so you can check her out when she's cold.

[Autofix]

Hi Damo,

you would be surprised how often it happens that a car behaves perfectly while i look at it and gives it's owner grief once it leaves. it's almost like i scare the poor things

As long as it is likely to play up then yes, you are welcome to book it in. It would be pointless for me to have it unless the symptom is there for me to chase.
Unfortunately it is likely to be 3 to 4 weeks before I can take it. Give me a call.

Alan

[prestigejs]

The relay is two in one it is a power relay and also the fuel pump relay on these. I took a lot of the problem as starting the car, not a lot has been mentioned about the general running.

Does the running change when the car is hot or cold.
Does the Engine sound flat.
Does the pitch of it change much if you rev it in neutral up to a higher range of revs
If you drive it in a low gear at high revs does the power loss get any better.

[Damo]

Thanks for your all your help lads

Does the running change when the car is hot or cold. - Yes it seems to improve the hotter it gets, on a very cold morning it can be very sluggish
Does the Engine sound flat. - Yes
Does the pitch of it change much if you rev it in neutral up to a higher range of revs - not really
If you drive it in a low gear at high revs does the power loss get any better. - Yes it improves, starting off in first gear though its quite slow to get going it doesn't at all have the burst of speed like it used to