LEXIA - Unable to delete Injection errors...Jim, anyone?

[paulcornwall]

Hi, I'm trying to resolve a problem with our newly purchased C8 HDI. It smokes more than I like and the fuel consumption is down at 29mpg. I've done the first reading with Lexia this evening and wanted to delete any existing errors in order to get a true set of faults after a test drive. However when i came to the Injection module it continually says "Communication Error". Can anyone help, why would it say this? how to i get them deleted?....Jim?

It also states "Particle Filter Clogged" which I'm assuming is the dreaded FAP...looks like I've just inherited someone else's money pit. I also see faults such as "Temporary fault turbo pressure. Elecreovalve short circuited to earth or open circuit" + "Temporary fault turbo pressure signal. coherence with atmospheric pressure" + "Temporary Fault Exhaust differential pressure signal" etc etc.

I cannot delete any of the above faults so cant tell how valid there are, however would the symptoms of excessive smoke at low speed acceleration and poor mpg indicate a clogged FAP?

[Mandrake]

Paul you're not alone. When I put my Lexia on RichardW's Xantia HDi 110 it was able to read the engine ECU and do everything except clear the fault codes, we tried a few times then gave up. It was saying Communication error, same as you. I was running Diagbox 7.02 at the time.

On all the other cars I've put my Lexia on (none HDi) I've had no problems clearing fault codes, so it seems to be peculiar to the HDi ECU's.

Hopefully an HDi owner will come along with a suggestion.

[citroenxm]

Im not sure why your not gettng communication error unless theres a fuee blown for the diagnostic socket preventing certain reading..

All the hdi ive worked on and theres a few have had no problem.. im sure i got a niggley that there was one and it was a fuse or something

Dont worry about the temperary faults that sounds like someone has been disconnecting electro valves under bonnet but not reset the car after..

Id check all fuses first.

[paulcornwall]

Without deleting the current errors its going to make it difficult to get a proper set of fault codes for diagnostic. If Jim is around, could we arrange a diagnostic session?
Power seems ok but flat in some gear i.e on a incline in 2nd gear at lower speeds. I've been reading about removing the FAP altogether what are peoples thoughts about this?
Also in lexia there is a option under Maintenance to perform some sort of procedure on the FAP, whats this all about?

[Mandrake]

Im not sure why your not gettng communication error unless theres a fuee blown for the diagnostic socket preventing certain reading..

I doubt its a fuse.

When it was happening to me on RichardW's Xantia the Lexia established communication with the engine ECU no problem, read the fault codes, read live sensor data and from memory we also tried actuator tests, all with no problem. However attempting to clear the already read fault codes resulted in a "Communications error" and a loss of connection to the ECU until we went back in through the menus again.

One thing I've thought of though - we only tried to clear the fault codes while the engine was running - perhaps on some ECU's the codes can only be cleared when the key is on but the engine is not running ? Worth a try...

[paulcornwall]

One point i forgot to mention, all other menu's can be deleted fine, its just the "injection" menu I'm having problems with, and of course thats the menu seems the most useful considering the car symptoms (excessive smoke, and poor mpg)

[citroenxm]

You can make the engine "Re-Generate" the FAP Filter with the lexia.

Make sure your not in a built up area, as the Lexia makes the engine rev at 3k for 2 mins, then at 1,500, then at about 4k (Rev figures not exact, but give you an idea what it does)

I did it once on a C5 2.2 .. it warns you too that its a nosy session...

[RichardW]

It continues to run OK, even with the stored codes.... Still throws the ABS light now and again, but that rear sensor is not getting tackled till it has to be - although that will no doubt be when it is snowing....

[DickieG]

One thing I've thought of though - we only tried to clear the fault codes while the engine was running - perhaps on some ECU's the codes can only be cleared when the key is on but the engine is not running ? Worth a try...

Yep that's the case, many ECU's won't clear codes with the engine running, only with ignition on engine stationary.

[DickieG]

Hi, I'm trying to resolve a problem with our newly purchased C8 HDI. It smokes more than I like and the fuel consumption is down at 29mpg. I've done the first reading with Lexia this evening and wanted to delete any existing errors in order to get a true set of faults after a test drive. However when i came to the Injection module it continually says "Communication Error". Can anyone help, why would it say this? how to i get them deleted?....Jim?

It also states "Particle Filter Clogged" which I'm assuming is the dreaded FAP...looks like I've just inherited someone else's money pit. I also see faults such as "Temporary fault turbo pressure. Elecreovalve short circuited to earth or open circuit" + "Temporary fault turbo pressure signal. coherence with atmospheric pressure" + "Temporary Fault Exhaust differential pressure signal" etc etc.

I cannot delete any of the above faults so cant tell how valid there are, however would the symptoms of excessive smoke at low speed acceleration and poor mpg indicate a clogged FAP?

The faults you list sound familiar to one's I've seen on S1 2.2 C5's where there's a problem with the particulate filter, the turbo pressure problem can apparently be down to a blocked particulate filter causing turbo back pressure.

The big problem on an early C5 is that it's all but impossible to reset the particulate filter ECU after the Eolys tank has been refilled and the filter cleaned/replaced without replacing the system's ECU. The get out that many have done is to remove or use a masonry drill to make several holes in the particulate filter and load a different software program onto the engine ECU using a Galetto cable so that the engine then runs without the particulate filter system.

When I've worked on a C5's (IIRC 3 of them) I haven't noticed any excessive exhaust smoke but some of them ran in a limp home mode at various times.

I take it that you've re-booted Lexia and the laptop you're running it on and tried connecting with the injection ecu when the ignition turned and the engine is stationary?

[pale]

Hi there,

i'm new here, drive a C8 2.2 HDI and have the same problem as above. Lexia can read codes, and clear them, but the engine codes like injection codes resulting communication problems.

Anybody solved this problem?

Thanks

[Rhothgar]

10 year on and I have the same issue with the 110HDi.

Nothing to do with wiring, fuses or anything f like that.

I’ve stripped down the OBD socket and re-tensioned the pins. Still no joy.

To add to the joy, my Lexia light flashed and it became flaky. The insides don’t look good.

I think it’s an ECU firmware corruption at least in some part. Not sufficient to stop the car running but…

Unable to find my old shot ECU from a few years ago. Had hoped to plug that in and if OK Inwould have transferred all the integrated chips across.