Lexia Diagnostic Result

[bddeazeley]

Hi Folks,
I already posted this Lexia Diagnostic Report under my original topic thread 'Lexia Locations Central Scotland' but as yet I have received no responses and as my MOT time is approaching I hope there are no objections to me reposting it under a new topic in the hope that it will be more prominent.

Many thanks to David Hallworth for his time and knowledge in carrying out a Lexia diagnostic session on my Xantia 2.1TD. It was a fascinating experience and David is very competent and knowledgeable and made me most welcome.

The following is the diagnostic report and I would appreciate the opinions and advice of members on this report.

PERMANENT FAULT - DIESEL THERMISTOR
PERMANENT FAULT - CAM POSITION SENSOR 1
PERMANENT FAULT - CAM POSITION SENSOR 2

FAULTS CLEARED, FAULTS STILL EXIST

PERMANENT FAULT - DIESEL THERMISTOR
PERMANENT FAULT - CAM POSITION SENSOR 1

CAM ACTUATOR TEST - ENGINE NOTE CHANGED AS EXPECTED.
PUMP TIMING AT 3000RPM - 0.0 - 1.0 EXACTLY, NO DECIMAL PLACES.

ENGINE RUNNING FOR 2 - 3 MINUTES:

PERMANENT FAULT - DIESEL THERMISTOR
PERMANENT FAULT - CAM POSITION SENSOR 1
INTERMITTENT FAULT - CAM POSITION SENSOR 2

I have some electronic knowledge and it strikes me that to have faults on 3 separate sensors is unusual and may point towards connection problems rather than sensor failures. However there is no substitute for experience and I would be grateful for the 'wise owl's among our members to pass their opinions on my diagnostic report.

Thanks,
Brian

[CitroJim]

Hi Brian,

That's an interesting set of faults.. The good news is that within the EPIC pump itself these are no sensors despite the report suggesting there might be. I've had a few EPICs in bits and bar the ESOS electrovalves everything is mechanical.

The thermistor report will be caused by either the green coolant temperature sensor or the Inlet Air Temperature sensor in the inlet (clod turbo) pipe with, from memory, a grey connector on it.

The cam sensor faults are likely to be caused by a duff Needle Lift Sensor on No.4 Injector; these are a common failure and can be checked by disconnecting the two pin connector to it and checking its resistance. It should show around 100 ohms from memory..

The connector to it can come loose and disconnected so that may well resolve the issue.

Else that the crank sesor may be duff/intermittent but that's a most unusual occurrence.

EPIC systems can be badly upset by air ingress, either from a bad filter housing, perished pipes or perished leakoff pipes; they also suffer badly from clogged filters. Note that the filter element is much longer than the similar looking 1.9TD one and a 1.9TD one will not do...

Air is a real enemy to these pumps and it's worth definitely excluding this as a potential fault.

[bddeazeley]

Many Thanks for your quick reply Jim. The more I read up on the Lucas Epic pump the more confused I become lol. I am now beginning to wonder if there are 2 or more versions of the Lucas Epic as I have read that there are integral sensors within the Lucas epic pump which cannot be removed. Have a read at page 13.1 of this Renault Kangoo/Clio technical description which actually gives a resistance reading for an integral pump temperature sensor.

ftp://host217-41-52-224.in-addr.btopenw ... /3303A.pdf" onclick="window.open(this.href);return false;

I have replaced the green temperature/coolant sensor and the air temperature sensor with no improvement. I also replaced the fuel filter housing and top cover with brand new ones as I was getting some air bubbles in the fuel lines which has been resolved but again there was no improvement. The MAP or is it MAF sensor has also been replaced and the needle lift sensor reads just over 100 ohms. I have not changed the crank sensor as yet (a bit more inaccessible) but I read that even if it is faulty the Lucas Epic control module substitutes the needle lift sensor signals and operates ok. I will try the crank sensor for elimination purposes as I already bought a new Citroen one recently.
Your opinion on whether the Renault pump description is the same as the Citroen Xantia pump fitted to my 2.1TD would be appreciated.
Thanks again for your help,
Brian.

[CitroJim]

You've done your research well Brian The Renault one looks very similar and differs only in detail - mainly electrical.

The odd thing is I've been all over an EPIC and stripped one right down (there’s a guide on how to do it on here somewhere) and for the life of me I've never found any sensors or anything electronic within and that's what is really confusing me.

It drives me to want to check again as I think I still have a scrap EPIC here that once leaked and was 'repaired' by someone putting a seam of epoxy resin all around it's periphery!!! I'll pull it down again and look closer when I have a few minutes spare..

You've already checked all I'd have thought might have had a bearing on the problem.

You're right about the NLS taking over from the crank sensor and vice-versa if one goes duff.

Bear with me on this - I currently have a Bosch mechanical on the bench undergoing a rebuild so can't pull a Lucas apart in its presence - The Bosch will get jealous of being in the company of a technically superior pump!!!

[bddeazeley]

Thanks for your reply Jim. I have not looked at the car yet as it is in daily use and I am creating a plan of attack . Electronic components are relatively reliable and to have 3 sensors faulty seems unlikely. When I look at the wiring diagram in the Renault technical description of the Lucas Epic pump there are a number of ECU connector pins that are common to the components within the pump which makes dry joints within the Epic ECU a possibility. What intrigues me is on reading various forums about Lucas Epic posts the symptoms I have ie diesel knock etc are mentioned often with many suggested causes but none of the threads culminate in a definitive cause and often the problem is resolved by replacing the Lucas Epic pump with a mechanical Bosch pump which makes the Epic management system redundant. This raises the question was the original fault caused by the Lucas Epic pump or by the now redundant Epic management ECU? I will need to get my old magnifying glass cleaned up and examine the ECU pcb for dry joints. I will keep you informed.

[CitroJim]

It's a good point Brian. So many get a downer on the EPIC but actually it's a very excellent pump indeed. I'd rather work to resolve the issues than go down the mechanical Bosch route but that's just a personal view. Not many seem to share it.

If it will help I can scan up the Citroen version of the Renault documentation and the applicable wiring diagrams but again, it'll take me a few days now as life is about to get very busy again. let me know if you'd like them.

Your thoughts about going over the ECU with a magnifying glass is good but you may find your efforts somewhat thwarted as it was either very early ECUs or later ones (can't remember which now) were 'potted' to prevent tampering and also prevent fixing too..

Beware that if you try swapping the ECU yu'll need to know the keypad code if it's an S1 and if an S2 you'll also need the matching transponder module and CPH (body computer) and a Lexia to reprogram the keys to the new transponder and CPH. The ECU cannot be reprogrammed to another transponder or CPH once initially married up.

[bddeazeley]

Hi Jim, Thanks for your reply and sorry for the delay. I have been getting my Hyundai Terracan 4x4 back on the road again and through its mot in order that we can go caravanning this summer. Just had a good trip to Norfolk. I have been googling lots about the Lucas Epic and the confusion over the sensors in the pump and I came across this timing kit for the Lucas Epic 7135-286 (photo attached) Can I ask have you any knowledge of such a creature? It is possibly for a newer version of the pump than is fitted to my Xantia 2.1. I have also attached a photo of what is referred to as the rotor sensor which may well be where my problems lie.

Sorry I am unable to attach the photos for now just getting the error message 'Sorry, the board attachment quota has been reached' but if you try this link hopefully you will see the timing kit.

http://dev4.racingbazar.hu/alkatresz/gy ... _kit_elado" onclick="window.open(this.href);return false;

If you scroll down this Fiat Forum you will see the photos of the Rotor Sensor.

http://www.elektroda.pl/rtvforum/topic1760468.html" onclick="window.open(this.href);return false;