Okay, not had my 2002 2.5 crd long but am beginning to experience most issues related to these cars.I recently put up a thread concerning my airbag light which used to come on with a chime and then periodically go off and come on again.Well now the light stays on so i will get sorted soon as.Now though the car immobiliser light comes on with a blink and then stays on after bulb check.Sometimes it just stays on meaning no catch on the engine to turn over, when it blinks and stays on i can crank but turns off after about 3 secs.I disconnected the battery fuse and tried disconnecting the IOD fuse but no change. Next i take the terminals off the battery for at least 30 mins or overnight and bingo the immobiliser light goes out and i can drive,great! Stop car, go and do what i need to,and get back only to find same problem.I got the codes it stored after the battery was reconnected and when the problem re-appeared and this is what we have:
P0340 Camshaft Position (CMP) Sensor Circuit
P0620 Generator Control Circuit Malfunction
P1130 Oxygen Sensor Circuit Low Variance (Bank 1, Sensor 1)
P1652 Powertrain Induced Chassis Pitch Output Circuit
P1685 - Invalid key received from the SmartKey immobilizer module (the thingie in the ignition that makes sure you are using a correct key)
P1685 - SmartKey immobilizer module reports bad key used (this is common if you tried to put the wrong key in!)

Seeing all these makes me a tad nervous as it looks serious.When the car goes it drives great so i don't know what to do before sending it to an expensive repair center.The keyfob (2 button) has not worked since i have had the car so any relationship here is not relevant i think.All terminals in the fusebox look ok, Please can somebody shed some light? I have looked at other threads but not seen anything relevant to this kind of problem.

 

What can you do/check that's not going to cost much? -- As you mention "expensive repair centre".
You mention "generator control circuit malfunction" as erco. P0620. I assume they mean 'alternator' rather than generator. Generators have not been used on vehicles since the 1950s.
So my check would be to borrow, beg or steal another GOOD battery, fit it and see what happens. There's a chance it could fix the problems. If it doesn't then at least you've tried.
The rationale here is that disconnecting the battery as you did removes stored glitches from a micro. As soon as you reconnect battery and drive, the alternator hash (your erco.) disturbs the micro again. Alternator hash is much worse with a bad, sulphated battery. (see my pictures of alternator hash on another posting). This kind of fault AND CAUSE is not unknown with other makes.

Leedsman.

 

The definitions of the error codes are not quite correct.

It's not unusual to see a crank or cam position sensor fault in the history. If it's an active fault it probably won't run so we can assume it is a stored fault.

The P1130 is fuel rail pressure in a diesel, for petrol it's an 02 sensor. Again, it's not usual to see an 1130 as a stored fault.

P1652 is a communication bus error

P1685 is a SKIM failure or comms failure

Most code readers will only be able to get codes from the ECU and not the other modules. This means there may be another faulty module that is affecting the data bus and you would not be aware of it. Testing a data bus really needs an oscilloscope to track down the fault. Without a scope all you can do is a visual inspection of wiring and test for a short or earth with a multimeter.

The alternator voltage fault could also have an impact on the fault. As Leedsman said if the voltage is rough or spiking it could make the modules throw a wobbly and corrupt the data bus.

Regards
Richard

 

Thanks chaps for the advice.I left the battery connected last night and checked this morning and the light went out after check on ignition! I think i'll try the battery route first as a mate has a spare.The one that's in there has the poles sitting on the right as you look and the leads as a consequence are being pulled a little bit more than they possibly should.The poles look a bit chewed as are the clamps.It isn't one of the best makes either so i'll start with this.At least now i have a few options to put to the auto electrician should it come to that.I at least may sound like i know what i'm talking about should i need to go there! One thing though is that this all started as soon as the weather started to take a nosedive and get colder and wetter!

 

Be cautious about your check battery. The condition won't be known. Test it with a heavy-current test-lamp for a minute or two. My heavy current test-lamp is two car headlights wired together. This will draw about 10amps. It's a rough and ready method if you don't have a 'scope for looking at the hash from the alternator (which should be in the low millivolt range).
Another trick is to use TWO batteries at once WHILE DRIVING. This means clamping jump-leads onto the battery, putting the wires through the passenger window and clipping onto a second battery parked in the passenger footwell. BE VERY CAREFUL NOT TO GET REVERSED POLARITY, OR TO SHORT ANYTHING WHEN YOU SHUT THE BONNET/HOOD. If you suspect this could happen, put an old piece of thick carpet over the battery terminals. A few seconds care here could save anguish later. This safety advice isn't really for you the poster, but for anyone else reading this who is perhaps not much of a car mechanic. I had a very nice Citroen C4 written off by an electrical short in the ABS unit causing a fire. I was as mad as hell, because I liked the C4 and it had no faults otherwise.

Leedsman.

 

Okay so not yet been able to check other battery, and as i took my lad to school it behaved and again to the shop.Come out of shop and no go.Took off terminals and walked home(10mins) coffee(10mins), walk back to car.Reconnect and still no go.This time i took out the battery fuse and IOD fuse and left it for 10 mins.Reconnect neg terminal after i had scraped up the fuses with a screwedriver to bring back to silver and hopefully help with flow.Bingo car starts, get home and 5 times check on ign the light goes out.Coincidence? We'll just have to keep an eye for now.Just about to go out so we'll see.

 

Well just an update.Have been out since it has behaved and had to start it a number of times, all ok.I can't believe that all the aggro was just because a slightly coloured fuse needed a clean up.If things stay good i think i'll go around all terminals and fuses and make sure they are all cleaned..Big thanks to all who posted advice.