Citroen C4 (2006) weird fault codes with iCarsoft (CAN fault?)

[t-mu]

Hi,
I was using iCarsoft CR MAX to read fault codes from Citroen C4 (year 2006). I noticed that some of the codes were quite weird looking. Reader gave me codes P000A F0, P0EE4 FE and P0C0E FC (see attached image).

I found a listing of fault codes for C4 and based on that and fault descriptions I think I was able to figure out that those given codes should be like this:

airbags and pretensioners ECU
P000A F0 -> F00A
anti-theft alarm
P0EE4 FE -> FEE4
passenger door module
P0C0E FC -> FC0E

For some reason only last four characters are "real code" and even they are mixed up.

I was wondering if anyone has ever stumbled on something similar when using these "generic" code readers?

F00A code indicates a CAN bus fault for the "airbags and pretensioners ECU". Does anyone happen to have a some kind of diagram regarding CAN network topology for the C4 (2006), or any ideas if there are any common denominators for those listed modules? I was wondering if a problem with a CAN bus could somehow cause these weird looking codes on the reader?

-Teemu

[EdMar]

Hi

New on forum but might be able to help,

Sometimes there is extra info available with a code ,
tools such as Bosch KTS will often be able to show 'variants' of the same code,
giving a clue as to what triggered it. open circuit / short circuit etc.

iCarSoft my be displaying codes in a slightly more 'raw' format

see https://www.csselectronics.com/pages/ob ... mple-intro
bit long but a skim read can give you an insight to the lower level comms between scanner and ecu

I my experience a little batch of comms failure code is typical of a weak battery,
voltage dropping too low while cranking, often when someone turn the key straight to cranking.

Often secondary modules drop off the can bus when the battery voltage goes low.
A tool that can read manufacturer codes can pickup low voltage codes from modules.

try this sequence,
Ignition on, give it a few seconds to let everything boot up
check / clear codes,
Start engine
Check codes

If codes are there try clearing with the engine running, and see if they stay off.

Some battery / alternator testers can log minimum cranking voltage
Its easy to wind up chasing you tail looking for CAN problems that are just 'Brown Outs' taking modules off line.
Hope it helps

[GiveMeABreak]

You haven't stated what engine this is for, so please provide the VIN which will help. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[t-mu]

Thanks for the replies and information EdMar and Marc.

Originally there was a problem with an alternator and that caused a dead battery. There was a long list of different comms fail codes and others after I replaced the alternator and I think most of them were just caused by a low battery voltage as EdMar also mentioned.

These are actually codes that came back after I did a code clear. I cleared the codes after I replaced that alternator and charged the battery, took a short drive and read the codes again. I'm planning to do another check in a few weeks time to see if there are any changes. At the same time I'll try to check those mirror, washer and reverse light issues.

VIN is VF7**************[VIN obfuscated, can be read by forum staff]
Engine is NFU/TU5JP4 1.6

[t-mu]

I got a confirmation from iCarsoft that those weird looking codes are caused by a software bug. They are looking into it.

Regarding the actual C4 fault codes. It seems that there are few new ones after the last code clear. They are intermittent misfires at least on cylinder 3 (P1336 and P1339):

engine management ECU Fault | (2)
P1336 status: intermittent
Content: Fault misfire on undetermined cylinders
characterisation of the fault: Not characterised
cause: local

P1339 status: intermittent
Content: Fault combustion misfiring on cylinder number 3
characterisation of the fault: Not characterised
cause: local

I haven't done any checks yet, but I was wondering if cylinder order is counted from flywheel/gearbox side or from auxiliary belt/crankshaft pulley side? I read somewhere that it could be counted from flywheel/gearbox side and just wanted to be sure.

I'm starting by checking the spark plugs. If they need to be replaced, is there any suggestion regarding the brand (Bosch, NGK, Denso) and is there any specs for correct spark plug gap size? Engine is TU5JP4/NFU 1.6.

-Teemu