Engine immobilised

[alanlondon]

Driving slowly, about to park, 2003 C5 1.8 petrol manual suddenly cut out. "Engine immobilised" flashed up on LCD screen briefly, followed by "Economy mode enabled". As you do, I tried to restart the car; it turned over without any problem, but would not fire. The Rev Counter did not move one iota; that would indicate, usually, that the Crankshaft Position Sensor has failed.

With "Economy mode" displayed I decided to charge the battery. I already had a fully charged battery from another car and replaced the existing with the new, following the bsi reset procedure. On turning over, no firing.

Before I go further, I am somewhat concerned about the "Engine immobilised" message. Before I start testing the cps, has anyone had a similar experience and are there any pitfalls I should be looking out for?

All contributions gratefully received!

[wheeler]

The Rev Counter did not move one iota; that would indicate, usually, that the Crankshaft Position Sensor has failed.

I wouldn't say that's a very good indicator of the condition of the CPS.
Is it still showing the engine immobiliser message now when you try to start it?
Have you done any kind of diagnostic check on it at all?

[alanlondon]

Thanks for the reply wheeler.

The immobiliser message was shown briefly after the car stopped. No further message. Even with the changed battery I have "economy mode" displayed.

I have put an OBC reader on it, which is only worried about the Evap system.
I will be testing the cps, but I thought I would ask the question before delving further. As I have few tools at home (and will have to bring some back from my garage), I am not about to become oily without being able to test everything at once!

If the immobiliser is thought to be a red herring, I will just work through air, electricity and fuel as usual.

[wheeler]

The immobiliser message was shown briefly after the car stopped. No further message. Even with the changed battery I have "economy mode" displayed.

Economy mode on this car has nothing to do with battery condition or state of charge.
Does your OBD reader have a live data function? This would likley be your best bet to see what the crank sensor is doing.

If the immobiliser is thought to be a red herring, I will just work through air, electricity and fuel as usual.

I would think it is a red herring as the immobiliser will not cause the engine to stop, it only prevents it starting in the first place.
Is the timing belt OK? can you see the camshaft through the oil filler cap opening to see if its turning when you crank the engine?

[alanlondon]

Not bothered about economy mode; it was just the display coming up with immobilised.

Not the obd I have here. I do have another with live read!
With the issue being not now starting, that's why I asked the question about the immobiliser!

Timing belt is still working! It is looking like cps. I'll bring a few tools back and try it tomorrow evening if it isn't pouring down. At least it is staying light now.

[alanlondon]

Have finally had enough time to look at this again!

Cranks, does not fire.
No spark.
No power to fuel pump.
No wipers.
No electric windows.

Have put a decent-ish code reader (snap on), but do need a Lexia thingmajig for a full llst.

Have an idea what it probably is but would love thoughts from those more knowledgeable with Citroens.

Car as listed: 1.8 petrol C5. Would hate to not have this car, it is the company "van"! It has been up and down the country collecting parts from all over for the past 5 years.

[wheeler]

The no wipers or electric windows is likley due to the fact the car is in eco mode.
Did your snap on unit communicate with the injection ecu?
My first guess would be the under bonnet fusebox but i would like to do further checks to confirm.

[alanlondon]

Thanks for the tip about the economy mode; I didn't think of that.

Frankly the snap on was almost useless! (which I found surprising) No connect to injection ecu.

Have looked at the engine fusebox, as that is the unit I suspect and, used electrical cleaner on the contacts, with no result. Made sure to photograph the connectors, so I could check contacts by magnifying on my phone, all looks good. Still no power to fuel pump. I have even starting looking for a used fusebox, but if there are other avenues to explore I am all ears!

[alanlondon]

I forgot to say...

...I do have 0.56 volts at the fuel pump.

[wheeler]

Frankly the snap on was almost useless! (which I found surprising) No connect to injection ecu.

My feeling here is that there was nothing wrong with the diagnostic equipment, If there is no fuel pump operation & no spark you will likely find that the ECU is not powered up. No ECU power up = no communication with diagnostics. If you unplug either the coolant temp sensor or MAP sensor (which ever is easiest to get to) & switch the ignition on you should get 5v at one of the wires on either of these, If you dont the ECU is not powered up.
Inside the under bonnet fusebox there are 2 internal relays, one provides power up to the ECU & the other supplies the fuel pump, ignition coil and some other components, so still looking like a fusebox issue. I assume you have checked all the fuses??

I forgot to say...

...I do have 0.56 volts at the fuel pump.

I Think we can safely say this is 0 volts, just picking up some back voltage from somewhere.

[alanlondon]

Yes, all fuses checked. All good.

Very good point about the ECU not firing up.

I'll check tomorrow and post results.

This is one of these cases where brain fade comes in and one stops thinking logically. Thank goodness you are here to help Wheeler!

[alanlondon]

5v at MAS. Still can't connect to ecu. Odd.

Will borrow another scanner from a friend.

[alanlondon]

A quick update.

Unfortunately unable to borrow another scanner. For some reason my friend didn't want to come back from his holiday in Spain to lend it to me!

ECU must be powering up. Tested fuel pump with external supply, working fine.

Pulled fusebox. No nasty smells but that proves little. However did find the maxi fuses. Now if only the handbook listed which fuses are which correctly. Even found more fuses in the glovebox fusebox which I hadn't seen before. I will be testing more fuses this afternoon.

Should this turn out to be the fusebox, unfortunately, most of the identification marks appear to have weathered away.

All suggestions welcome about further work.

[Hell Razor5543]

Something that might be worth trying is to clean the blades of the fuses. A couple of months ago my C5 threw up a suspension fault. After faffing about a bit I found the fuse blades were very tarnished (not burnt), which had increased the electrical resistance. I did a BSi reset, and (while the battery was disconnected) I popped each fuse out and (using a model rail track cleaning rubber) cleaned the blades (they went from dull grey to shiny silver), and she has not had an issue since.

[alanlondon]

To make matters worse, the fuel pump retaining ring will not go back on. It seems like a deformed tank; it was a struggle to remove.

The only thing I can think of is to split the ring and then hold it on with a large Jubilee clip.

Anyone any better ideas?