Thread: Disco 4 Engine System Failure Warning - beware!

Originally Posted by jonrichkl

HThe car limped home with no power for 15kms where I turned it off and on again and now all seems fine, power returned and drives normally although the red triangle remains and I suspect the shift patterns seem very slightly different.

I haven't done a hard reset but have done the lock unlock and ignition cycling recommended elsewhere on the forum. None has seemed to make any difference but as I said the car drives fine now.

If the car is driving Ok then most likely it is OK and the red triangle is still there because the fault code is logged into the system. Now some people will advocate leaving it and getting the code read at the dealer (or read it yourself if you have the gear) so at least you know what the issue was - and thats fine.

For me I like to clear codes and if the fault comes back it is real and not a vagary if the electronics. So if it was my car and as you said is running OK but do not have a code reader/reset tool - I would do a hard reset to clear all the codes in the car.

Hopefully your red triangle goes away and thats it - if the fault comes back the the code is relogged for the maintenance people along with any other codes logged since the reset.

If the fault does come back after the hard reset I would be loathe to drive it.

Also you said that after you code the red triangle you limped 15km home - I would not do that. Red triangle - stop straight away!!!!!! Then switch off restart etc and if OK - go home. If the fault is still there then a hard reset on the side of the road. On restart and all is OK - go home. If the fault is still on - then decision time - drive or tilt tray or call for other LR professional help.

Good luck with it.

Garry

Originally Posted by garrycol

I would do a hard reset to clear all the codes in the car.

An absolute myth!
As the engine is now running OK, don't clear the code so that the cause can be determined and corrected as I'm sure that you don't want the same fault to occur again.

Originally Posted by Graeme

An absolute myth!

Ok I bow to your superior knowledge but it does seem to work on my car.

Cheers

Garry

Disconnecting the battery for a moment or 2 will stop an ecu from running thereby causing it to restart when power is reconnected. Whilst fault codes will remain, excepting for those that clear after a preset number of successful restarts or drive cycles without the error condition, if the fault condition is not detected then the fault code can appear to have been cleared. However the earlier mentioned ecm logic error fault code will remain as a current fault even though the triggering conditions don't currently exist, presumably because its a programming bug rather than an operational fault condition for which a corrected version of the s/w is required to prevent the fault re-occurring.

I've not got a FCR (yet) so I guess I'll have to wait until the mechanics open up tomorrow.

I guess, I was just wondering, given its driving normally now, if it was more likely to be a software error/sensor misread rather than something more expensive.

This is just my IMHO....

I've not read all the replies and I'm sure someone has already mentioned this...

I fail to see how "Engine Systems Failure" is a DANGEROUS Land Rover Discovery 4 thing, bluntly I think the comment is a bit ridiculous. Its a generic system protection fault, while the exact wording is more Ford than other brands, they (as in all manufacturers) ALL have some form of when there is a detected issue that could potentially damage a major component such as a engine or transmission the computer system will put the vehicle in a limp or power restricted mode to protect these components.

The computer system doesnt know the current driving conditions, going up a hill, towing a caravan, overtaking a truck etc etc etc.

While I'm sure it was a hair raising experience, its not a Discovery 4 fault.

Regards
Daz

Originally Posted by DazzaTD5

The computer system doesnt know the current driving conditions, going up a hill, towing a caravan, overtaking a truck etc etc etc.

Not quite true - the ECU does know when the engine is under load eg going up a hill, towing a caravan, overtaking a truck etc - in its simplest form my FC 101 has a vacuum gauge and when it is in those conditions it is in the red (well when you drive a 101 it is nearly always in the red) and when off the throttle it is in the gray - so a high tech ECU in a D3/4 will sense increasing load via a miriad of inputs - eg sucking air compared to road speed and throttle position, high throttle position compared road speed, high MAP etc.

I can get the red triangle and various forms of restricted performance in my RRS when towing anything over 1 tonne (never happens when not towing) by simply spirited driving - flooring it when doing over 100kph and flooring it when going up hill. If driving relaxed and towing it does not appear.

I no longer stop even if the engine has shut down if on a straight multi lane highway - into neutral, switch off for 2 seconds and restart and all is good. Normally not long enough to loose power assistance on the steering so has to be done only in the right conditions.

Cheers

Garry

Originally Posted by DazzaTD5

The computer system doesnt know the current driving conditions, going up a hill, towing a caravan, overtaking a truck etc etc etc.

As cruise control is a function of the TDV6 ecm, the ecm obviously knows when CC is active.