2001 V40 in Limp Mode

[310den]

Not in any dictionaries but: HERE and scroll down to Automotive.

[druid]

Originally Posted by happy diver

Is the current Oxford defn of limp mode any time a car doesn't work properly

Originally Posted by 310den

Not in any dictionaries but: HERE and scroll down to Automotive.

I just assumed it was a feature of the turbo car so it goes back to a low power map that wont do to much damage, a "safety" setting. I doubt a Gdi has one?

[310den]

Originally Posted by druid

I just assumed it was a feature of the turbo car so it goes back to a low power map that wont do to much damage, a "safety" setting. I doubt a Gdi has one?

All cars that have an ECU will have 'limp mode'. It is just a generic term that is used and you are correct in saying a safety setting to prevent any damage to your car by using preset levels for each sensor overwriting the problem until you get it fixed, for any petrol or diesel, turbo or not. It is just a term that has stuck and will probabaly make it into dictionaries in time.

[druid]

Originally Posted by druid

That video is excellent and worth watching, i had tickover trouble on mine and ended up cleaning the throttle body, now, it's sweet. Lot of people say burn it! but only a few really mean it.

You will need this aswell. If it stalls just restart:-

Learning function if GDI engine.On GDI equipped cars, when the ECU is replaced or the battery is reset (disconnected), an idle learning function for the ECU will be required

Idle Learning Procedure

1. Start the engine and warm the engine until the coolant temperature reaches 85c or higher.When the coolant temperature is 85c or higher, you only have to switch the ignition to the ON position.
2. Turn the Ignition to the LOCK position to stop the engine.
3. After 10 or more seconds, restart the engine.
4. Run the engine at idle for 10 minutes with Transmission in neutral (P for Auto), air con and heater off.
5. Stop the engine.
6. Restart the engine and run it at idle for 10 minutes with Transmission in neutral (P for Auto), air con on at max cool, fan high speed and windows open.
7. Repeat steps 5 and 6.

Note:
1. When ambient temp is 20c or higher and the air con has been continually operated, step 7 may be omitted.
2. During idle in steps 4 & 6, when engine operation switches from lean operation to stoichiometric operation, engine stall can occur.
In this case, clean the throttle body (throttle valve) thoroughly and repeat step 1 and the subsequent steps.

[DWeed144]

So once the problem is fixed do I need to reset the ecu to get it out of "limp mode"??

[gatos]

Originally Posted by DWeed144

So once the problem is fixed do I need to reset the ecu to get it out of "limp mode"??

You may have to do so, only if the car is having difficulties revving. I have a spare GDI at the moment and the car is working perfectly fine. Even when I had the battery disconnected for two weeks, it was running smoothly without the ECU needing to re-learn its values.

Only a guess here, but it seems that the ECU requires this learning process when one (or more) parts of the engine are not working 100%, or if there is sgnificant coking up in the inlet manifold, throttle body and EGR.

[druid]

Originally Posted by gatos

You may have to do so, only if the car is having difficulties revving. I have a spare GDI at the moment and the car is working perfectly fine. Even when I had the battery disconnected for two weeks, it was running smoothly without the ECU needing to re-learn its values.

Only a guess here, but it seems that the ECU requires this learning process when one (or more) parts of the engine are not working 100%, or if there is significant coking up in the inlet manifold, throttle body and EGR.

It's a smart system that constantly adjusts to the little drop off's in settings. When it looses it , it tries to run a perfect map and wont do a very good job but it will settle out with high tickover as it starts to relearn - it would take a long time. Throttle body clean is easy, hell i did, it and it still works.
Once its all done it will work on the factory map, just not getting used to your driving style.

[DWeed144]

Thanks everyone for your help so far!
I have collected the car and had what could be called a 'leisurely drive' home. I was almost beaten by a hill, but in first gear at around 4mph I managed to make it over!!
I inspected the Throttle body, and it isn't too coked up, however it seems clear that the magnets/motor/spring has failed. I will remove this today and have a go at repairing....
Will put some pictures up soon.

[DWeed144]

So after getting the throttle body apart I confirmed that one of the magnets had come loose.
Having read a bunch of posts I knew to be really careful when extracting the shaft and handling the magnets....
Of course having successfully removed everything, and isolated the magnets safely from one another, I then proceeded with a slapstick routine which ended in snapping the loose magnet in half as it impacted with the other one!

Fortunately Gatos is nearby and had a spare Throttle Body available so he has saved the day!

Breaking the magnet caused it to reverse polarity at the break point which made repair difficult. I glued one half back, and once that cured, the second.

Having reassembled the unit it seems to behave normally, but I am assuming that if I were to reconnect it to the car, the mixed polarity of the repaired magnet will mean it will not behave as it should.



I will be back down to the car on thursday and will be testing my repair just to see what happens!

Thanks to Gatos for being so helpful!

[druid]

Give it a go,

Have a bit of faith in the Norse Gods of Volvo.

And Japan, it a Mitsubishi after all

We all do it!

and if that fails






we have Gatos