No cranking ECU communication error Citroen C5 1.6HDI

[davie206]

Hi guys I am looking for someone with some good knowledge of multiplex can systems on citroens or peugeots. The car I am working with right now iis a 06 Citroen C5 1.6HDI, dont know much about it's history although I do know when you turn ignition on the dash lights up like a christmas tree. Done a global scan with the lexia and found that none of the ecu's are having dialogue with the scanner apart from injection and suspension.I can not access injector faults as it wont let me read the injection ecu, I can however read the suspension ecu which had around 10 faults all relating to no connection to bsi. I then done a system scan with Bosch KTS which gave a fault for engine control module - no communication but the software will allow me to do is to go in to actuators where electric windows, horrn, central locking and lights all work but that's about it really! We have a newish fully charged battery on it now that whch has not really helped. When we try to start the engine there is no cranking at all, all we have is a click heard from the glovebox, if we have the glovebox open you can see the glovebox light go off when you try to start the engine then back on when you turn the key back to ignition on.

Anyone any ideas on this ? Sorry to rabble on but I guessed there might be someone on here better with diagnostics than I am lol.

[Hell Razor5543]

I do not know if the scanner is part of the issue, but (being French) PSA cars seem to ignore all but DiagBox (and earlier) diagnostics systems. There are members here on the forum with clones that should help, and they are normally prepared to offer assistance;

http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178

EDIT, just spotted you have already used a Lexia on it. I should read the posts before answering them!

[BX]

Right. First of all check the basics. Check that the ignition is actually sending power to the various ECUs and that the permanent 12V supplies are there too. Check fuses and check supplies to the various sensors such as the MAF. A missing supply to one of these may indicate a missing supply elsewhere which is causing the problem. Unfortunately I do not have a wiring diagram for the car in question but you can source one on Service.Citroen.com. You will need to set up an account and pay a fee to access this information. The option I have taken in the past is to order the RTA manual off Amazon.fr. As far as I know but I'm not certain the starter is electrically operated (as opposed to electronically). you can check continuity on the various buses by checking for the terminating resistors using a multimeter. Normally each end is terminated with 120 Ohms. Therefore probing the wires should result in a reading of 60 Ohms if both ends are connected. I cannot give specific information on this car as i do not know it very well.
In general I find PSA electronics quite straight forward and dependable especially in comparison with some of the premium brands whose reputations ooze reliability but which can be different in real life. Try fault finding the ones with the EIS and the SAM. How about valvetronic and VANOS anyone.

[RichardW]

I believe there is a relay in the underbonnet fuse box that activates the starter solenoid - and a fuse (10A?) that supplies it. I'm sure it's not unknown for the fuse to pop (repeatedly) giving a no-crank situation. Fitting a 15A fuse stops it popping. I would check this - and also is the starter getting current (granted it's a bit hard to get at on this engine!). If the fuse is OK, but there is no output to the starter, then the underbonnet fuse box is a candidate - faults with these are hardly unknown!

[davie206]

Thanks guys for helping out. Ecu is getting 12v from ignition. All fuses are good and starter is getting current
Im beginning to wonder if the fusebox is duff

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[wheeler]

Thanks guys for helping out. Ecu is getting 12v from ignition. All fuses are good and starter is getting current
Im beginning to wonder if the fusebox is duf

If the starter is getting current and its not operating that would kind of suggest either the starter is knackered (which wouldn't explain the other symptoms) or a main earth is broken/corroded (that could explain the other faults).

[Peter.N.]

Do you mean the starter is getting current to the large terminal from the battery or the small one to the solenoid? If there is voltage on the small terminal but the starter is not turning then the motor/solenoid is faulty.

Peter

[wheeler]

If there is voltage on the small terminal but the starter is not turning then the motor/solenoid is faulty.

.......or the starter motor is not earthed. This could also explain all the other symptoms as the starter motor is earthed via the main engine/gearbox earth strap.

[Peter.N.]

Could be but it depends where you connect the meter negative lead.

Peter

[wheeler]

Could be but it depends where you connect the meter negative lead.

Peter

Well yeah, but what I was saying is just because there is power going to the starter & its not operating doesn't necessarily mean the starter is faulty, you need to confirm that it has a negative connection/earth. I have seen loads of starters & alternators replaced in error for earthing faults. Had a Golf last week, a garage had replaced the alternator & battery, after a couple of days the battery died again, The nut on the gearbox earth strap was loose by about 2 full turns, 30 seconds to volt drop check the earth & 10 seconds to tighten the nut back up, battery charging again.

[Peter.N.]

I agree but its quite easy to check, if there is voltage on the connections and the earth is o/c you will have the same voltage on the case of the starter so its just a question of moving the test prod, in fact there will be voltage on most parts of the engine. Another way is to check for voltage between the starter/engine and battery earth, there shouldn't be any, if there is you have a poor earth connection.

Peter

[citroenxm]

I had this on a 1.6 hdi c5 and it puzzeled me fo a while.. The first thing though is there is a yellow 20amp fuse in The engine bay fuse box nearest the battery side. It was blown and it was the fuse for the starter solinoid. The starter was still getting power but it wouldnt turn because of the fuse. Eventually it did turn out to be a duff starter. I bought a replacment and put it on and its been perfect since.

[davie206]

Ok guys im now getting fault code U0015 no communication with engine ecu, can bus open circuit. Could this be caused by a faulty wire or connection wnywhere is the canbus system

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[addo]

It can also be an internal fault on the ECU. Has the car been jump started? Check grounding of the ECU housing.

[davie206]

Spent tuesday checking wiring again and fuses, relays etc. I cant see any damaged wiring or corrosion either. Finally managed to get communication to the ecu after cleaning all earths, disconnecting-reconnecting wiring and got the following faults with delphi p1590, p0104, p0238, p0183, p1471, p0122, p0405, p0193, p0104, p0113, and a 40A Oil level gauge - No symptom fault on the BSI module. I could clear all these fault codes and all I was left with was front left and front right abs sensor faults. A bsi reset does nothing to help and after disconnecting the battery and doing a bsi reset etc I now get no communication with engine ECU again - unable to read fault codes. ABS module is recieving power, ecu is recieving power, suspension ecu is recieving power.
I cant use lexia as the only module that it will communicate with it is the suspension ecu where it shows front body height sensor - Sensor power supply missing.
Also when scanning