First of all, my hat's off to you all for your input, it's very much appreciated!
I'd be very surprised if it started with an immobiliser issue.
Fuel pressure might be worth checking but I doubt it
My guess is the throttle body is giving a signal that makes no sense and thus the ecu is not opening the butterflies. I'd get another throttle body as well.
But I could be totally wrong.
C
Both throttle-body and pedal potentiometer has been replaced by brand new, contactless ones. First time starting after changing the pedal potentiometer, I could rev the engine although it wouldn't rev past 3,000 rpm or thereabouts (CEL was still on). Second time I started it after changing the pedal potentiometer it wouldn't rev at all. The throttle-body change did nothing to rectify this, but I did notice the engine running much smoother. I'll try the old pedal potentiometer again and see what effect this will have.
Worth noting here is that I've had both Circuit B and Circuit C mentioned in the DTC's. Circuit B before changing the pedal potentiometer and Circuit C both before and after changing the throttle-body.
Fuel pressure seems like it could be the culprit. Cheers for the tip! Is there any easy location to connect a fuel pressure gauge?
Hi Alecci
I had a similar but not exact problem last year.
I did not do the work myself but it was rectified after replacing knock sensors, crank sensor and starter motor.
The starter motor was interesting because it worked randomly and when it was taken apart there were a few areas of damage caused by the unit overheating.
All I can offer I'm afraid.
Ru
Every piece of advice is valued and appreciated!
Knock sensors and crank sensors have already been replaced, seems the starter motor is the remaining one to try out. It does crank the engine easily enough, however, so not quite sure. Did you notice any change in the starter motor's performance prior to replacing it? Mine is not working randomly, it cranks the engine every time you try it.
Due to the fact it starts ok without waiting for the checks I think this is immobiliser related, I think most other avenues have already been explored.
This does seem to be immobiliser, but the key code light is doing the opposite of what's expected. My problem is that occasionally the key code light doesn't go out, and at that time I can't start the engine...usually removing the key and re-inserting gets things working correctly. Sounds like a trip to an indie or an auto-electrician.
The key code light does not show up if I let the diagnostic check complete, but then the engine will not start. If I don't let it complete, it lits up after engine has started to run.
I'd plump for that too. The only times I've had the key code light on with then engine could be started was when the battery voltage was low. I think Alecci has changed his battery so, I would have thought there's either an immobiliser failure or there's a contact causing a voltage drop which leads to the sort of fault I had with a failing battery.
The other issues are definitely TB related, to my mind.
Yes, battery has been changed for a new one, and we even testet with a new one we borrowed. It did nothing to either ease or worsen any of the symptoms. I guess I could try with a third battery, but it seems far-fetched that I'd run into one used and two new defunct batteries.
I concur with your last statement to some degree, although changing the TB didn't solve the problem about not being able to rev the engine, it did noticably smoothen the engine's running. I basically sounds more even, smooth and healthy now. That's the reason I'm leaning towards the pedal potentiometer or something in between that one and the TB.
Steve
Hi Alecci, you are having some serious issues there sir. you have my sympathy, my car got gremlins like this and it took some sorting out. I suspect you may have more than one problem here, which is why you are getting confusing things happening. If you start the car without waiting for the checks to complete you now have an engine light and the little lock security light on? Is this right? The error code is P1225? if you let the checks complete it wont go? when it does start it wont rev up or produce much power? it sounds like if you let it complete the checks it decides there is a fault and won't go. if you get it started you have a fault and it does not go very well. I think the fact that the security warning comes on suggests it does not see the RFID chip in the key. If you have tried the spare key and that did not help then you need may need to look the induction loop in the steering column (see other thread suggestions). Note that my car occasionally does not see the RFID chip and starts but shows the little lock light. The engine runs fine like this, so this is not why you have no power. The lack of power is a limp home mode that car goes into when it detect certain faults. It will do this until the fault is fixed. You are not pressing the throttle pedal while starting are you? It really does not like this! The P1225 suggests either pedal sensor or the throttle body. Since you have replaced these then either new units are not right or you may have an ECU fault, or more likely a wiring problem. For the pedal sensor you need to check two things, first that the connector at the sensor is clean, none of the pins are bent and it plugs in properly and there is no corrosion (usually green fur) around the contacts. Secondly check the voltage it produces is within the spec, of 0.3 to 0.7 volts at idle, on both outputs (they must be in spec and the same). check the connector at the Throttle body and make sure the contacts are clean an not dirty or corroded. I would start documenting exactly what you try and what the car does, try to start it after every fix you try and note the response as you will need all the info you can get to diagnose this. I usually keep a little log book in the car and note down any odd stuff and any codes (although its been a while since i have had any). good luck sir!! Feel free to PM me if you want more detailed discussions, i know my life is misery when the cars dead.
Many thanks for the comprehensive advice!
I'm equally sure that there's more than one issue here, probably at least two; the engine being hard to start and it not performing as intended once started.
If I start the car without the diagnostic check I have a CEL and a key code light. If I do let the diagnostic check complete, I only have a CEL but the engine will not start.
I've not received error code P1225, but rather P
0225 and 0x1225 (no P in the second one, it seems unknown to the diagnostic software Unidiag).
When starting it will not rev above idle, power is hard to judge as I've not taken the car onto the street with no more than idle available.
Contacts for pedal potentiometer are like new, no bent pins, no grease or any other kind of dirt and no corrosion.
The contacts for the throttle-body I've not seen for myself (workshop did the change of throttle-body), so unable to say anything on this. Will check it out, however, if nothing else but to eliminate that cause.
I never press any pedals while starting the car, neither the clutch nor the accelerator.
Good idea about the log book, I'll keep that in mind for the future.
I suspect it may be either the ECU or the wiring as well, either one would be a PITA (pardon my French).
